Enspells conflicting with sambas is a pretty big thing.

I'd almost rather them just restrict future enspells to the first strike and double the intended damage than letting it activate on all hits.

Sure you might lose a bit if you double attack or are dual wielding a joyeuse, but that's nothing compared to the +50% damage bonus you can lose by excluding yourself from haste samba.

Besides, it's not like single wielding couldn't use the buff anyway.