Hello, welcome to forum.
You have good rosters.
I will suggest you leveling up rainbow color, so each color 1 heroes.
And I suggest you also leveling *3 heroes. You need stacking color and also class trial quest, and it will help your progress, because *3 heroes is fast to level other then *4 and *5.
You already lack of mats for *5, so Anzogh, King Arthur and Joon sit at 2.60. And also Richard 1.50, Obakan 2.36. They also will lack of mats. And basic stats *4 heroes 3.60 is better then *5 heroes at 2.60.
Do not focus on them yet. Just focus your *4 and *3 heroes. This game is design for long-term play.
For defense based on your rosters level.
Arthur - Anzogh - Cyprian - Joon - Obakan
For attack in raid/war/quest, best is level as many good heroes, then we can have many option to choose based on the oppenent.
Bring all good *4 heroes to 3.60. In order priority from left to right.
Red: Boldtusk, Sumitomo, Keleli
Blue: Kiril, Sonya, Boril
Green: Kashrek or Little John (both can make as your tank candidate)
Yellow: Wu Kong (good for titan and raid), Danzaburo
Purple: Proteus (best), finish Cyprian to 3.60.
Consider for keep *3 heroes:
Red: Rudolph, Squire Wabbit, Namahage, Hawkmoon, Nashgar, Azar
Blue: Gato, Valen, Ulmer, Gunnar
Green: Muggy, Belith, Brienne, Berden, Mnesseus, Hisan
Yellow: Bane, Gan Ju, Melia, Kailani
Purple: Balthazar, Tyrum, Chochin, Gill-Ra
Tips leveling (only my opinion):
- if you get *1 heroes on-color (same color) feed for your *4 heroes which is not yet 8/8 skill, you can 10x at the same times, but if the heroes is stuborn can not up the skill, use 1-5 at a time *1 heroes same color. And after has 8/8, you can feed *2 combine *1 heroes on-color and use 10x at a times.
- if you get *2 heroes on-color (same color) feed for your *3 heroes, use around 1-5x at a times.
So, slowly but with this plan, you have more choice, and feel your playstyle which is better to ascend and so on, or later you can ask in forum again.