So to the RL-5, its a fine weapon. Despite my dislike of .25 tons as a thing for IS tech, the RL-5 is not OP or anything.
Now, my feelings on the class of rockets is very different... small spammable packs of rockets are meh at best--they dont deal a lot of damage and the units that make best use of them are not in line with the scope of the rest of the game. An rl-5 isnt a great option even on a 20 ton mech... nor is the RL10, but the RL-5 just doubles the problem with 2x the hit rolls making it even better at being an annoying spammed item. And 3,000kg units or other very tiny vehicles that would efficiently use an RL-5 are so cheap and inconsequential that you would have 50 of them for the cost of a single heavy mech, and as a game first that game is unplayable/ boring. The most fair/balanced game is when both sides have equal numbers, and items like the RL-5 are so small that their only use is to break some sort of balancing somewhere, versus taking a 1 ton medium laser.
I guess I cant see how I would incorporate any RL that isnt the 20 into a viable unit, and this RL-5 would be the worst offender. The RL20, with the ability to clear mines, is the only RL I have found in my game play that is worth taking, despite the odd tonnage. Id hate to see a ferret vtol armed with a ton of these even more then id hate the ferret that used an equal tonnage in RL10s. That many hit rolls and cluster rolls from so many RL5s feels like a chore to roll out. It would mostly be a way, for 1 ton, to put super cheap/small weapons on tanks as crit buffers on all the facings so hits like stabilizer or weapon destroyed didnt roll up into worse conditions.