Let's put it this way, the gropho is the only Heavy combat mech that requires you to use a specific module to make use of all of its bonuses.
Mesmer does have an armor repair amount bonus, but that bonus suits that bot and would suit any other combat mech bot. I would happily trade the shield bonus on the gropho for the mesmers armor repair amount bonus, but i'm not so sure that mesmer pilots are going to agree with this change
Seth gets max accumulator, damage and crit chance, all useful for any combat mech build.
Mesmer gets armor repair amount, damage and falloff, all useful to any combat mech build.
Gropho gets locking time, damage and shield absorb rate? The shield absorb bonus is completely ***, i'm sorry to say it, but i'm shocked that it was ever designed like this in the first place. Gropho is now the only heavy combat mech that is forced to use a module that not many people want to use in order make use of one of its major bonuses. This is utterly ridiculous. Why they would force people to equip a non faction specific module and use a hardly used specific build in order to be fully effective is beyond me.
Since when the hell were heavy mechs "specialised"? Light EW bots, EW mechs, those are EW specialised. Heavy combat mechs are just that, heavy combat mechs. Specialised versions will probably eventually come much later into the game development.