Like it,
Instead of spending weeks certing into one very narrow unit you can spend weeks certing into a unit that can be used for more than one thing.
I am sure you can choose to narrow your focus into a specific damage type but the basic upgrades/certs like armor and speed should carry over if you decide to throw on an AI instead of an AA gun, for example. (of course this is if I understand the cert system they talked a bit about over the last few months).
also
Shouldn't players be able to discern by the type of gun on top of the tank, or on the wings of the aircraft, what it will do? Plus the type of ammo it is firing could be a dead give away but it might be too late at that point lol.
Think of it as another thing to separate the new players vs the PS2 vets, a skilled(basically someone who has played often enough to gain the knowledge..) PS2 player might be able to notice, at a quick glance, that the tanks approaching his squad are fitted with AA guns and frontal armor plating and tell his squad to try and flank it with ground forces or something along those lines.
Recognizing what each unit is in an approaching army's squad/platoon is great info for command (and can make scouting more helpful since you will probably need either some kind of long range viewer (a Binocular type device or a scope from a gun like sniper rifles) or scouts/infiltrators leading the way in to see what you got to fight against.
Anyway, I don't think this will ruin the game by any means. Plus they can always add more stuff after they get going. If they said they got a 5 year plan for the game I assume that includes regular new content (new guns, tanks, aircraft, maybe naval warfare, new certs probably, maybe even a new "class" down the line a bit).
IDK just my .02
PS