Completely disappeared without a trace. And deserters, who should have been brought back from previous installments of Heroes.

There aren't enough pegasi and the Swamp race. Efreet are scarce, which is bad. We also need more eyeballs. There are enough dragons already. Maybe they'll bring bears back in the expansion. What else... oh yeah, nagas. They've completely ruined the nagas. In short, there's a shortage of favorite units.

Added 3 minutes later

Why do you need the Swamp?

We need the Swamp because it's part of Heroes of Might & Magic. And without it, something is missing.