Oh no, Phaun is very useful in providing me some extra food when the dragons fail to find the next piece
Seriously though, I think all towers are ridiculously useless feature in the game with the reload times that they have and minuscule benefits they offer. I'd say to make them useful, SP needs to convert them to some permanent effect. E.g., Midarian could be just "increase gold production 20%" without any cooldown. Jewelem could do a couple of gems a day + store them (e.g. up to 5 or 10 gems). Broodby/Ramsey/Damona/Hanzo/Phaun could be converted from a "effect+cooldown" into just some permanent perk, e.g. "Your food grows 20% faster" or "Your dragons breed 20% faster".
If a cooldown is desired, then it may be some second, powerful feature that requires maybe even longer cooldown. Sort of what "Exertion" ability in MtG does. For example, for Midarian it may be some lump sum gold bonus, or for Damona it can be "Finish all breedings currently in progress".