Don't forget that Clan Warrior turnover is very high. Warriors test-down, die in combat (or a Trial of Grievance, or Trial of Bloodright Grand Melee), or simply age to the point where they are deemed fit to be nothing more than sibko instructors (around age 35-40, if unblooded). If the Clans retained their solahma warriors for another 10-20 years of service, their toumans would be huge (or at least the pool of available warriors would be, don't know about equipment).
When Clan Wolf was forming the Dragoons, I suspect that a lot of those "going down and out" warriors, instead of dying, ended up in the Dragoons, during that period. So they siphoned off a lot of those people. Mercenaries of ages 30-40 would have appeared normal and natural in the Inner Sphere. They might have been test-downs by Clan standard, but could be considered veteran and elite soldiers to Inner Sphere eyes.
On top of that, we don't know if creating the Dragoons left Clan Wolf short-handed for a while. Their Clusters and Galaxies could have ended up a little short-staffed and short-handed for a few years after creating the Dragoon, until new warriors refilled the empty slots. For all we know, they temporarily deactivated garrison clusters of freeborn warriors (who had lost most of their personnel to the Dragoons) and used frontline units to fill the gaps until those "losses" could be made up via new freeborn cadets selected from the lower castes and new trueborns coming out of the sibkos.
Clan Wolf could have also let go of a lot of warriors to form the Dragoons, but then boosted the number of freeborn warriors they would take in for that year (or a set period of a few years) to refill the empty slots in their Touman. If the Clan generally only accepted 50 freeborns a year (just theoretically speaking), maybe the Wolves upped it to 100 that year and used the extra warriors to replace what was lost. So for the next 10-20 years, more freeborns than usual would have appeared in the Touman. That number would have dwindled again as attrition took it's toll and as new trueborns graduated and replaced that aging generation of freeborns.
So no, I don't think it means their Touman was or is bigger than listed. There are ways in which it could have happened. The personnel was there, and could be obtained in the ways described above. We already have a pretty detailed accounting of where much of the equipment came from. Most of it was mothballed stuff dating back to Exodus years and early Clan history.