If you into a walling team, I can fill you in on another three pokemon for your team (however I am unsure about the three you mentioned as I have no experience with them myself)
Number one
Blissey@Leftovers
Trait: Natural Cure
Nature: Bold (+def -atk)
EVs: 252 Def, 252 HP, 4 Sp Def
-Aromatherapy
-Thunderwave
-Softboiled
-Seismic Toss
Standed walling Bliss, provides team support with Aromatherapy, Thunderwave to cause status, Softboiled is a self healing move and Seismic Toss to do 100 damage to anything in Blisseys way (providing Blissey is at level 100)
Bold and Max Def EVs helps Blissey to survive Physical hits a little bit better
Number two
Skarmory@Leftovers
Trait: Keen Eye
Nature: Impish (+def -sp atk)
EVs: 252 HP, 252 Def, 4 in either Atk or Sp Def (speed doesnt matter since you'll be going last with whirlwind anyway)
-Drill Peck
-Whirlwind
-Spikes
-Rest/Roost
Drill peck for STAB, Lay down some spikes then cause damage to your opponents by switching them with whirlwind, rest or roost for recovery purposes (preferably roost since you got Blisseys aromatherapy taking care of status problem)
Number three
Milotic@Leftovers
Trait: Marvel Scale
Nature: Bold (+def -atk)
EVs: 252 HP, 252 Def, 4 Sp Def
-Aqua Ring
-Mirror Coat
-Dragon Pulse/Ice Beam
-Surf
Like Blissey, Milotic has a huge base Sp Def, so adding EVs and Bold Nature makes Milotic a strong dual wall, with its special attack it can also fit back
Aqua Ring provides Milotic with constant HP recovery, which along with leftovers helps Milotics staying power. Mirror Coat is an egg move, but reflects Special attacks back at the opponent with twice the power, Surf for STAB and Dragon Pulse/Ice Beam as a filler
*notes*
-There are people better than me who would probably suggest something different than I, but I am starting to pick up on the Natures and EVs of some pokemon (most noticeably the ones i mentioned)