Hesitating on Florence's CE

Hi everyone, here's the team I'm planning to play but I'm hesitating on Florence's CE while I don't have her bond CE (I use the suit with the order change skill to cheat in Jeanne if needed).

I gave Florence Chaldea's scholars to help with the NP gauge and give her more survivability for the HP, but I also have maiden of halloween for survability (tough not maxxed). (I don't have gentle affaction btw)

In case of fights where I want to open with Jeanne and Florence in backups then Florence wield Ox demon king to give a +65% Buster Bonus to Cù, and Jeanne wield Vessel of the saint

Any advices for a potential better CE for Florence in the scenario where she is in the avant-garde ?

Also when I get the bond 10 CE for Cù, is it better than the +25% buster one ?

Thanks in advance everyone : 3

In case the pic is too little :

Waver 10/10/10 with his bond CE
Gale 10/10/10 with Chaldea's scholars
Cù alter 10/10/10 with

Back up
Jeanne 6/4/10 with Kaleidoscope
Mash 3/3/3 (I'll up her skills after Jeanne so don't worry, I won't forget Kouhai : p)