If by enough you mean 2 (not counting the old IIDX one as themed charts weren't really implemented yet plus the map choice was... unique), then, no, I don't think it's enough actually, since it's usually rhythm game songs that bring out the most interesting songs in my opinion. Now I'm not saying it should be changed, but I'm a bit disappointed that since there are 3 bemani games coming out at the moment (Reflec Beat colette being the third one, not released yet though) there really was some potential to work with.
Regarding this chart, I don't really know why HAMELN is there; doesn't sound very relaxing if you ask me.
In general... Let's just say I wish the CtB chart was also the standard and Taiko chart.