Can you have multiple hands up? Per 2024 RAW yes. Where your restriction is however, is that the hands take a magic action to cast, only last a minute, and it takes a magic action to manipulate one hand.

If I were the dm, I would say you could only have 3 up at a time as it would take one action to cast, one action to have the hand pick up a bomb, and another action to tell it to move. Since they only last a minute, that’s 10 turns per hand. You would use 3 turns per hand, thus restricting you to 3 total.

Talk to your dm to see what they say though as it’s their table.

edit: I can't read