Missionary and Mystics - unbeatable combo?

[PhilD]

In an online game today, I noticed that a Missionary that gets Second Wind from a Mystic, can reuse his ability. While this is at least part logical from the units' descriptions (he cannot be affected by lasting effects), it seems a bit over strong - once you've got a Missionary and lots of Mystics, you can neutralize an equal number of enemy units.

Of course, you need a game with both Orcs and Afflicted, but still - it feels wrong.