All I run now with the Catapult are 2 K2's, I ditched the others. Very similar, I just can't decide which layout I like the most, so I bounce back and forth.
The faster build, about 82kph with speed tweak:CPLT-K2 AC10 build
Groups: 1: AC10's 2: arm ML's 3: all 4 ML's
Rarely want to fire all 4 ML's with the AC10's due to heat, and not much reason for 2 groups of 2. Fire group 2, then follow with group 3 and the cool down period takes care of that. However, when out of AC ammo, it's nice to have the 4 in a single group.
Drawback: 300XL engine $$$$$$$$$$
AC10's are pretty tough compared to a gauss rifle
Slower, but everyone loves a gauss-cat.CPLT-K2 gauss build
Grouped same as above K2.
I like having energy weapons to fall back on with enough power to still be effective. Sometimes I do drop 2 ML for ammo, just depends.
Even with 4ML's, heat is still just 1.3, which is pretty nice.
Drawback: 4 tons of gauss ammo can go quickly.