In my server Sailor Sakura and Kimimaro are used in ranked with a double/triple healing team to keep both Sakura and Kimimaro hard to kill and with massive aoe damage. So I would say she's pretty viable to get as soon as you can.

On the other hand, you have enough for 4* Tenten and that will be massive damage in it's own right. Up to you, which way you want to go or feel more comfortable.

I would go with Sailor Sakura personally since I intend to play long-term and War Tenten is in later treasures.