There's no even remotely complete accounting of the forces involved on either side. The novels are not exactly helpful either; to be honest, they're written by somebody who clearly wasn't famillar with the BattleTech universe. Although this problem is hardly unique to the MWDA novels...
Getting back on topic!
The Highlander forces on Northwind consisted largely of green infantry and armour (Possibly converted IndustrialMechs). Two BattleMechs were explicitly identified; Tara Campbell's Hatchetman and a Koshi (I forget the pilot's name). They were said to be the only BattleMechs on the planet, although that's the sort of claim I'd take with a grain of salt, or put down to again issues with the author not knowing the world.
The Steel Wolf invasion force consisted of at least six Clusters of Wolf troops, based on the number of Star Colonels identified. Most of these seem to have again been composed of nothing but infantry (both conventional and Battle Armour) and armour. The only cluster explicitly identified was the Crusaders, under Anastasia Kerensky. Her custom Ryoken II was present, but I don't recall any other BattleMechs being explicitly identified.
Finally there was Jack Farrell's lance of "mercenaries". This consisted of Jack Farrel's Jupiter 2, 'Dagger' Di Jones' Hatchetman, a Mad Cat III and a Firestarter (That my personal headcanon says is Pyro Peterson). They are the only force that are completely accounted for.
