i agree with the idea, but not the implementation. the main problem is, an engineer and even a pilot can be an effective gunner (e.g gungineer), but a gunner cant be a pilot or an engineer. that speaks to the flexibility and utility (or lack of) in some classes.
imo these are the best options
1- make some items class-exclusive, ie. only pilots can choose claw, only eng can choose mallet
2- give gunner more options (being able to use spyglass while sitting on a weapon, a new tool that feeds a new clip onto a weapon someone is using so the subsequent reload is quicker, not only bullets but more gun attachments like 2x scope, variable zoom, a more defined crosshair sights, infared sights through cloud etc.) taking some ideas from cod unfortunately, but they've ironed out all attachment ideas thruout the years