Should I summon with this roster and mats?

Hey all, on my junior f2p account I’ve had insanely good luck and my pulls outpaced my mats by a decent margin. I have ascended (but not maxed) a single 5* (Grimble), and I have several 5s and 4s waiting for their last mat. They are all 3/70:

Kadilen
Isarnia
Grazul

I’m also sitting on the following 3/60 4* heroes, any of whom except green I can upgrade at any time:

Colen
Kelile
Melendor
Boril

So, I’m wondering if I should

A) 10-pull Season 3 immediately to potentially broaden my candidates for this first rainbow, or

B) Focus on what I have and save summons for down the road?

One downside of B is that this account gains mats so slowly that I would run out of heroes to level months before I accumulated the mats to ascend a new set. The fact that this account progresses slowly seems to point to summoning now, so I have the best possible bench to select from.

Thoughts?