I must have gotten that from the original House Kurita book or the 20 Year Update, because I wasn't intending to change anything. Since the CM was set before the FM, I wasn't restricted to its contents. I know I didn't create it on a whim. Likewise for special abilities of units. The Combine FM was set after the Invasion, but the CM set prior to and during the early period of the Invasion. In some cases I tried to bridge differences from 3025 to the FM, but most of the units didn't have specialties and did require formulating them from whole cloth.
The Davion CM was written with the same concerns and intent, though it was so long ago I couldn't tell you specifics about it anymore. The Force Manuals are different, so some changes were required to the old ms, but I didn't make those for the Davion book and thus have even less certainty over specifics than I might have had.