I went with the following and went 1-2 with it due to bad die luck... If your mechs score one hit between the two of them and are shot to bits, victory is very hard. 8s and 9s were the average. I even had a "confirmed" critical failure on an artillery roll, despite Improved Targeting.

HD Loki + -/+2/+1 generic pilot and Command 249
SSw Mjolnir 87

Formation of:
SSw SM1 Tank Destroyer 43
2x SSw Sortek Assault Sled 58

Formation of:
3x HD Undine Battle Armor 57

HD Gossamer VTOL 40

SSw Hadur FSV 46

HD/SSw +1 Damage faction pride 20

600 even