When amateur thieves break into his retirement home it’s upto an aging war veteran to kick their a**, risking his slip disk

This reads very well as a premise for a comedy.

I would make the stakes higher, money is less relevant for these people than their memories.

I would also expand the story to include more of the MC's retirement home commrads:
After thieves break into their retirement village, a war veteran must lead a group of seniors, walking aids and all, to save their most cherished possessions.

This is probably not very helpful, but this logline makes me chuckle. Sounds like something I'd enjoy watching.