Aranthir, if you recall "Dark Messiah," regularly summons these kinds of little dragons (but skeletal ones, and this is their only appearance in the game).

Necrodrakes have traditionally been weaker than living dragons in the HoMM series, by a factor of 1.5-2.

In Heroes 2 and 4, they are quite good. In the second game, the skeletal dragon isn't much weaker than the green dragon in terms of stats (even though it lacks breath and magic immunity). In the fourth game, they are also decent. Of course, they are inferior to megadragons and black dragons, but they can compete with magical dragons.