Not sure how it works with smaller mechs, but for Assault Mechs I am now a firm believer in double main weapons.
I am also on like day 10,000 of my original campaign! Will get the expansion next month I hope.
Anyway, I am running the 5 skull, rep 20 or 23 with impunity. I purposely haven't tried a rep 25 one yet. I want to be back in practice before I try 8-12 Elite Assault mechs on!
Here's my main lance for 5 skullers:
Yeah I still have all my originals. Have been sure I lost each of them at least once, especially Behemoth a few times.
I have been having so much fun flying around and hunting rare stuff and smoking the bad guys I haven't really been thinking about the expansion. Behemoth has made head shot kills on assaults and heavies 3 times in a row! The other times only once in awhile. Soften them up with fire support then move the 2 AC 20 killers in and watch the parts fly!
The jump jets are a MUST imho. Keep those evasion hash marks up and live.We blow stuff up real good!