It's true that the races and jobs off-set in this fashion, but what would be more impressive is if it worked out (which it probally did. Heck, that might have been the best party in that area at that time).
I'm glad to see more people mixing and matching race/jobs like this. It takes away from the stereo-type that all mages MUST be Taru, and all tanks MUST be elvaan.
Now wouldn't it suck if ALL White mages were Tarutarus? Yes it would. Where's the variety.
I, myself, play an Elvaan RDM/BLM. Yes, I don't have the UB3r MP that a taru does (and sometimes I wish I did), but I don't mind.