I posted the challenge, and have finally had the time to put together my own group. Gotta be honest, when I first posted this I didn't have an appreciation for how frigging cheap these machines are, and didn't know it'd be that easy to go for a full Maniple of mechs in the BV that my group uses as a baseline for a single lance of modern machines.
First Century:
Emperor EMP-1A
Lumberjack LM5/M
Crosscut ED-X4M-E
Crosscut ED-X4M
Carbine CON-9M
Second Century:
2x Wasp WSP-1
2x Commando COM-1A
Cattlemaster CTL-3R3
Total BV = 5948
First Century has an emphasis on ranged combat, able to actually respond with real firepower at the kind of ranges most proper military forces can fight at. The Emperor and Lumberjack are the clear stars that will try to attract and absorb attention whenever possible. The Crosscut-E will surprise many folks by mounting an actual heavy gun, though it'll probably try to fire from cover whenever possible. The Carbine will likely do the same being the most fragile mech in this group, possibly staying behind hard cover entirely and firing indirectly. The remaining Crosscut is the escort. It'll stay in cover as well and spot for the Carbine, only advancing if enemies try to get into close combat so it can mash the Go-Away button.
Second Century isn't that varied, but there just aren't that many Primitives or IndustrialMechs fast enough to perform recon or flanking duties. The Wasps are, well, Wasps, they'll do what they always do. I'm hoping the Commandos will prove a nasty surprise, since most folks expect Commandos to mount a much more close-in weapons array, especially since the Marians build their own model with exactly that. The Cattlemaster is slower than the rest, but is mainly there to provide that Century with some LRM support even when operating independently of First Century.