[fdfgyu]

Ships are big, if this were a real problem it would be easy to find space for a "lab sized" laser.

ICBM warheads are small. Space in drones and fighter jets is at a premium.

This is military.

[bluGill]

While ships are big, there is a lot they want in them so space tends to be limited if the ship wasn't designed to do that. Military places the big things and the rest in between