OU Sunny Day Team; Help appreciated

Hey there. I wanted to make my first competitive team so why not make a Sunny Day team? This team will revolve around Lilligant (main sp. sweeper) and Ninetales (Inducing Drought). With an addition with Dugtrio into the team, I can keep threats of Ninetales away with Arena Trap.

Here is my team at a closer look.

Timid Ninetales @ Air Balloon
Ability: Drought
EVs: 252 Sp. Atk/4 Sp. Def/252 Spe
Sunny Day, Solar Beam, Fire Blast, Nasty Plot
The core of the Sunny Day team. I figured that I may run into other weather inducers so just in case, Sunny Day is there when I need it. I wanted Ninetales to deal damage too so I when I have the time to setup, Nasty Plot will be there and an attack of choice.

Modest Lilligant @ Life Orb
Ability: Chlorophyll
EVs: 252 Sp. Atk/60 Def/196 Spe
Quiver Dance, Sleep Powder, Giga Drain, HP Ice
The main Sp. Sweeper. Of course, I would need the sun to be out on the field so I wouldn't her out without the sun unless I have to or its neccessary. If I can get a Quiver Dance in, her sweeping job will be easier. Sleep Powder to open up to get free hits. Giga Drain for healing and STAB damage against Rock and Grass. And HP Ice for pesky dragon types mainly.

Jolly Dugtrio @ Focus Sash
Ability: Arena Trap
EVs: 252 Atk/252 Spe/4 Def
Earthuake, Stone Edge, Reversal, Momentum
Revenge killer and the man to rid of pesky Terrakion, Tyranitar, and Heatran. Someone has to check these pokemon for Ninetales in order for her to continue her job, and Dugtrio seems to fit the role perfectly. STAB Earthquake for some nice damage. Reversal mainly for Blissey and Chansey. Final move, I can't decide. Momentum sounds great but Sucker Punch could be another option.

Bold Cresselia @ Leftovers
Ability: Levitate
EVs: 252 HP/252 Def/4 Sp. Atk
Reflect, Thunder Wave, Ice Beam, Moonlight
A wall who can take advantage of in a powered up Moonlight in sun. She would provide Reflect and Thunder Wave support and can safely switch in for suspected Earthquakes that are aimed toward Ninetales and Dugtrio. Ice Beam is the choice of offense (unless there are better choices). With its nice natural bulk, I couldn't resist but try to toss Cresselia into my team.

Adamant Scizor @ Choice Band
Ability: Technician
EVs: 252 Atk/248 HP/ 8 Sp. Def
U-turn, Bullet Punch, Superpower, Pursuit
The main physical sweeper. Checks up on enemy Tyranitar/Bisharp. Reading up on it from Smogon, Scizor makes a great partner for Cresselia because of this, allowing it to take a hit from these 2. I don't know how often I may encounter them but its nice to have him around just in case. Plus, I was in need of a steel-type and a physical sweeper. With Reflect and Thunder Wave support from Cresselia, Scizor can switch in on physical attackers more safely and allows the first move. Pursuit can catch Ghost types or retreaters off guard.

Bold Forretress @ ? (Was thinking Lum Berry?)
Ability: Sturdy
EVs: 252 HP/252 Def/4 Sp. Def
Stealth Rock, Rapid Spin, Volt Switch, Gyro Ball
The item is kinda questionable. If I'm hit with item clause (or when I play Random Wi-Fi), Cresselia or Forretress will have to give up a Leftovers. A Lum Berry can be given to Forretress to rid of status effects. Meehh... anywho. Stealth Rock and Rapid Spin support to help my sweepers sweep. Slow Volt Switch for a free switch in. Gyro Ball (I'll be sure to get 0 IVs in Speed) for a strong STAB move.

I could replace Cresselia for Blissey or Chansey for a more durable Special Wall. Plus Blissey can use SR while Forretress can use Spikes. But the synergy between Cresselia and Scizor sounded great. Ugh I don't know.

On the subject of Lilligant, would Venusaur be better for a Chlorophyll sweeper? Quiver Dance sounds great on Lilligant but Growth sounds just as great on Venusaur, plus hes more durable. I'm a little stumped. So many possible substitutes.

I'm open to any team swaps, but I'd like to keep Ninetales and Dugtrio somehow but you may suggest replacements for them if needed.

Scizor is pretty much dead weight on a Sun team because its Fire weakness is enhanced in there. Infernape is better on Sun teams, mainly because you need more Fire STAB abusers than just Ninetales itself:
-Flare Blitz
-Close Combat
-U-turn
-ThunderPunch/Mach Punch
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Choice Band
Ability: Iron Fist

or
-Fire Blast
-Close Combat
-ThunderPunch
-Hidden Power (Ice)/U-turn/Mach Punch
Nature: Naive/Hasty
EVs: 180 Atk/76 SAtk/252 Spe
Item: Life Orb
Ability: Iron Fist

or
-Close Combat
-Fire Blast/Flare Blitz
-U-turn
-Hidden Power (Ice)/ThunderPunch
Nature: Naive/Hasty
EVs: 64 Atk/192 SAtk/252 Spe
Item: Choice Scarf

or
-Fake Out
-Stealth Rock
-Overheat
-Close Combat
Nature: Hasty/Naive
EVs: 252 Atk/4 SAtk/252 Spe
Item: Focus Sash

While Forretress suffers from the same increased Fire weaknesses as Scizor, I can't bring myself to replace it, since you need Rapid Spin. Also, don't use a Bold nature when you're using Gyro Ball; the Bold nature should only be used when Forretress is using Hidden Power Ice:
-Stealth Rock/Spikes
-Rapid Spin
-Volt Switch
-Gyro Ball/Hidden Power (Ice)
Nature: Relaxed/Bold
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers/Shed Shell
Ability: Sturdy

I'd suggest testing out both Lilligant and Venusaur to see which one works better for you.

I'll suggest Donphan over Forry to alleviate the Fire-weakness problem. It has access to Rapid Spin, Stealth Rock, and STAB Earthquake. It counters Heatran (can pop Heatran's Balloon with priority Ice Shard) and can proceed to KO it with EQ or scare it off and lay down Stealth Rocks.

Donphan @ Leftovers
252 HP 252 Attack 4 Def (or you can opt a defensive spread of 252 HP/252 Def/4 Attack)
Impish Nature (+Def -SAtk)
-Earthquake
-Rapid Spin
-Stealth Rock
-Ice Shard

The set is pretty standard.

You can also replace Scizor with Volcarona to have more sun abusers.
Volcarona @ Life Orb/Leftovers
252 SAtk 252 Spe 4 HP
Modest/Timid Nature (+SAtk - Atk/+Spe -Atk)
-Fiery Dance/Fire Blast
-Bug Buzz
-Quiver Dance
-Hidden Power Rock/Ice

Fiery Dance is when you want a reliable STAB that has the chance to increase your SAtk by 1, while Fire Blast is when you want sheer power blasting anything that doesn't resist it to ashes. Flamethrower can be an option to if you want something in between those two. HP Ice for annoying Dragons or HP Rock for a bit more coverage over Bug, Fire, Flying and (which is also covered by HP Ice).

Heatran is a great member on Sun teams, too. It absorbs Fire-type attacks (aimed at Lilligant or Venusaur) to raise its own output; it resists Solar Beam which is commonly seen on Sun teams; it has Earth Power to take care of nonfloating Fire-types; it has good Special Defense that can be used to abuse Roar and Stealth Rock; it can go well with Cresselia's defensive bulk to have more stall time and wear down your opponents with WoW or Toxic; it can function well as a revenge killer, too.

Heatran @ Air Balloon/Leftovers/Life Orb (Shed Shell can be used if you're afraid that Dugtrio will trap you)
252 SAtk 252 Spe 4 HP
Modest Nature (+SAtk -Atk)
-Overheat/Fire Blast/Flamethrower
-Solar Beam
-Earth Power
-Hidden Power Ice/Dragon Pulse

Heatran @ Choice Scarf
252 SAtk 252 Spe 4 HP
Timid Nature (+Spe -Atk)
-Overheat/Fire Blast/Flamethrower
-Solar Beam
-Earth Power
-Hidden Power Ice/Dragon Pulse

Solarbeam is your best answer to Dugtrio on the switch. Else, it could trap and outspeed Heatran. If Heatran is carrying Air Balloon, it can withstand Dugtrio's attempt to pop the Balloon by a Sucker Punch and proceed to KO it with Solar Beam provided Dugtrio does not have Focus Sash.