Tyranitar can't use Stealth Rock with Assault Vest, FYI. Physically defensive Tyranitar is preferred, since the Sand will take care of its Special Defense:
-Stealth Rock
-Crunch
-Stone Edge/Ice Beam
-Earthquake/Fire Blast
Nature: Impish/Relaxed
EVs: 248 HP/252 Def/8 SDef
Item: Leftovers
Ability: Sand Stream
Considering I love the monotype tier, I'll give this a shot.
The only thing I feel should be reconsidered is the Regirock set. I know you said that you're hesitant on changing it, but hear me out. Regirock needs attack investment if you're going to use it as an all out attacker. With its high defense and Assault Vest, it's bulky enough to take a few hits. I would recommend changing around its EVs to something like this:
Regirock @ Assault Vest
Ability: Sturdy
EVs: 252 HP / 252 Atk / 4 SDef
Adamant Nature
- Drain Punch
- Ice Punch
- Stone Edge
- Earthquake
This way, you're getting a lot more bang for your buck.
As far as other teammates go, I have a couple suggestions.
If you want another power house hitter, Mega-Aerodactyle could be what you're looking for. Personally, I would use this set:
Aerodactyl-Mega @ Aerodactylite
Ability: Tough Claws
EVs: 252 Spd / 252 Atk / 4 HP
Adamant Nature
- Thunder Fang / Taunt
- Aerial Ace
- Stone Edge
- Earthquake
Although, I do see a lack of special attackers on your team. There's not much to choose from, but there are a couple plausible ones that each offer their own advantages.
Omastar @ White Herb
Ability: Shell Armor
EVs: 252 Spd / 252 SAtk / 4 Atk
Naive Nature
- Shell Smash
- Hydro Pump
- Earth Power
- Stone Edge
All Omastar needs is one Shell Smash, and you're good to go. With its secondary water STAB, it can fend off ground types that would otherwise demolish your team. There's Cradily, but Cradily doesn't really pack that much of a punch. With the lack of special rock moves, Stone Edge will have to do.
Lunatone @ Leftovers
Ability: Levitate
EVs: 252 SAtk / 252 HP / 4 SDef
Modest Nature
- Calm Mind
- Psychic
- Ancient Power
- Ice Beam
Another viable option is Lunatone. It might not look like much at first, but it does have its uses. The first, and most appealing, option is Lunatone's ground immunity. So, setting up a Calm Mind might not be so difficult. Once it does get a boost, Lunatone is surprisingly bulky, and can take a few special hits before going down. Although, lack of a special rock move and Lunatone's almost useless attack stat has Ancient Power as its only option.
I hope I helped a little. I wish there was more I could offer, but there aren't many rock types to choose from, and I'm not very experienced at team critiquing. Anyway, I tried my best and let me know what you think. I tried running a rock monotype team for a little bit, so I know how difficult it can be.
Aerodactyl doesn't have much use of Thunder Fang, tbh. It only hits Gyarados and Azumarill harder (who are already hit hard by Stone Edge), but that's it:
-Stone Edge
-Earthquake/Fire Fang
-Ice Fang/Aqua Tail
-Aerial Ace/Stealth Rock
Nature: Adamant/Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Aerodactylite
Omastar has no reason to use Stone Edge at all, given its inferior Attack:
-Shell Smash
-Hydro Pump
-Ice Beam
-Earth Power/Hidden Power (Grass)/Ancient Power
Nature: Timid/Modest
EVs: 4 HP/252 SAtk/252 Spe
Item: White Herb/Lum Berry
Ability: Swift Swim/Weak Armor
Lunatone is terrible. It's susceptible to Knock Off and isn't that strong.
Have you considered Rhyperior as a backup Talonflame counter?:
-Stealth Rock
-Earthquake
-Stone Edge/Rock Blast
-Ice Punch/Toxic
Nature: Impish
EVs: 252 HP/4 Atk/252 Def
Item: Leftovers
Ability: Solid Rock