Jobs are all around the kind of weapon that they use, that's the core identity above anything else so yeah you wont get different kind of weapons for 1 job.
It's not tank-specific either so why does it bother you only with tanks ?
If that's only for tanks and you do care way too much about it, the jobs aren't for you that's it.
And earlier in the game's lifespan it used to have different kind of shields the big ones and the small ones with different stats depending which one you had on you, but they gave up that idea long ago.