The general idea as a electronic warfare tools is a good one,
Sadly the ingame version feels stupid because those ships do damage to others.
But thats a flaw of the entire holotech in trek, its just magic.

Take away the damage of the holoships, make them copies of the ships that generated them while cloaking the original ship.
Sorta like collecting the emissions of the original ship and projecting it to another place to evade incoming fire.