RTF is a global modification that replaces all towns in the game.

Excuse me, what didn't you like about the Phoenixes and the Thunderbirds?

Phoenixes created too much imbalance even with a small amount of health (because resurrection is too powerful an ability for a 7th-level town creature). Changing their stats too drastically either makes Phoenixes too strong or terribly weak. It's better to leave them as neutral creatures.