Walkthrough of HoMM3: SoD Campaigns

I also had a similar issue with a hero, but in the mission with Jame. Instead of Jame, they gave a random Druid, and that wouldn't have been a big deal, but as a result, no one could get the 30 Grand Elves, which made the walkthrough much more difficult.
Interestingly, all the skills were still the same. That is, even if they gave a random Druid with the "Intelligence" specialty, he might not have had the "Intelligence" skill itself. However, if he did, the specialty worked.