I came up with a system that allowed for lances bigger than 390 tons. I called them Omega lances. Had a fun set of tables for them too. Saves the extra roll to determine if you end up facing Vee, Mixed, or Mech lances. Also, it allows for you to occasionally end up completely outmatched.
Player Lance is Light
Roll Bot Lances
2 1 Med Mech
3 2 Light Mixed
4 1 Light Mech, 1 Light Vee
5 1 Light mech, 1 Light mixed
6 1 Light Mech, 1 Med Vee
7 2 Light mech
8 1 Med Mixed, 1 Light Vee
9 1 Med Mixed, 1 Light mixed
10 3 Light Vees
11 1 Heavy Mech
12 Roll on Medium Table
Player Lance is Medium
Roll Bot Lances
2 2 Light mech
3 1 Med Mixed, 1 Light Vee
4 1 Med Mixed, 1 Light mixed
5 1 Heavy Mech
6 1 Med Mech, 1 Light Vee
7 1 Assault Mech
8 3 Light Mixed
9 2 Med Mixed
10 1 Heavy Mixed, 1 Light Mixed
11 1 Med mech, 1 Light mech
12 Roll on Heavy Table
Player Lance is Heavy
Roll Bot Lances
2 2 Light mechs, 1 Light Vee
3 4 Light Vee
4 3 Light Mechs
5 1 Med Mech, 2 Light Vee
6 2 Med mech
7 1 Heavy Mixed, 1 Med Mech
8 1 Assault Mech, 1 Med Vee
9 2 Heavy Mixed
10 1 Assault Mech, 1 Heavy Vee
11 1 Hvy mech, 1 Assault Vee
12 Roll on the Assault Table
Player Lance is Assault
Roll Bot Lances
2 2 Medium mechs, 1 Light Vee
3 1 Assault Mech, 1 Assault Vee
4 1 Medium Mixed, 3 Med Vee
5 1 Heavy Mixed, 2 Hvy Vee
6 1 Medium Mech, 2 Medium Mixed
7 2 Medium Mech, 1 Light mech
8 2 Heavy Mech
9 2 Heavy Vee, 2 Med Vee
10 1 Assault Mech, 1 Heavy mech
11 1 Hvy Mech, 2 Med Mixed
12 Roll on the Omega Table
Player Lance is Omega
Roll Bot Lances
2 2 Assault Mechs
3 4 Hvy Vee
4 1 Ass Mech, 3 Med Vee
5 1 Heavy Mech, 2 medium Mech
6 2 Assault Mechs, 1 Light mech
7 2 Heavy mechs, 1 Med Mech
8 2 Assault mechs, 1 Medium Mech
9 3 Heavy Mechs
10 1 Assault Mech, 2 Heavy Mech
11 2 Assault mechs, 1 Heavy mech
12 3 Assault Mechs