Tactics for Conflux.

The guy was asking about something slightly different. The idea was that casting mass speed and mass slow would be preferable, and therefore mass bless could be delayed for a few rounds.
Regarding the topic - indeed, that's the case, so it's better to level up 2 magic skills, and the third one closer to the end of the hero's development, if needed. Water is generally good for the Conflux, I usually take it if there's a bless skill available.