PDF, 2nd Edition.
Page 132, Bear Cub
"Once a Star Commander in the Seventh Bear Guards, the Trueborn Cardine was badly wounded during the short war with the Draconis Combine."
Issue:7th Bear Guards died to a man on Tukayyid and were never reformed. 1st, 3rd, and 5th Bear Guards fought in the First Combine-Dominion War.
Correction: There's two routes available. Either Cardine was a member of the 7th who managed to survive the flames of Holth and then later fought in some unknown unit in the First Combine-Dominion War only to be wounded and stuck in the 54th PGC by 3075. Would put him about 41 in 3075 so totally in the realm of possibility.
Or, Cardine didn't necessarily fight on Tukayyid but was in the 1st, 3rd, or 5th Bear Guards during the First Combine-Dominion War instead of the 7th.