I would recommend leveling all your moe cards to 50 before you focus on babe/sexy cards. Moe cards get a lot more SED from levels 1-50 than the other two, and then it goes downhill.

However, if you have Akie Ibara, level her up asap, she gives you a better SED when fighting elite guards. If you don't have her, do keep going at the gacha, you can get her from there.