Some quick critiques
-Mienshao, as you said, can have health loss compensated with Regenerator; it's also a Pokemon that switches in and out a lot. Thus Hi Jump Kick would probably be superior to Drain Punch for its power.
-Is there any specific reason for Bulldoze on Forretress? I mean, I know you said it's for the Speed reduction, but on a Pokemon that won't be outspeeding enemy Pokemon and really needs some extra oomph, I think Earthquake would suit it better. Or, as Batl said, Payback works as well.
-Charizard has a Hardy nature, may want to fix that. And I agree with Batl; Wise Glasses is too weak to provide a useful bonus, Choice Specs/Scarf/Life Orb would most likely be a better choice.
-Cradily I think my big gripe with this set is it just doesn't do anything. Any potential use of Gastro Acid is easily averted by switching, and both its moves are fairly weak considering there are numerous Pokemon that bear resistances and/or immunity to both types. Also, lacking any status remover, its vulnerable to Toxic, or even getting stalled out by a simple burn. I think Rest would be better for at least some stalling purpose, along with maybe Toxic.
-I agree that you should really opt to change Tyranitar's EV spread. I think if you're aiming for a balanced defensive set, you should pour more EVs into physical defense, as sand gives your special defense a boost. Also, say a random 8 Speed EVs or so to outspeed enemy Tyranitars without speed may be a good idea.
-Overall, the team has okay synergy except for the whole Sunny Day/Charizard conflicting with Tyranitar. But solid nontheless.