THIS!! Keep THIS in mind. When I began I’d be leveling a hero, get what I thought was a better hero so would stop and start leveling, soon I had a useless roster of partially leveled hero’s.
Pick 5 hero’s of each element. Stick with leveling them until they are completed. Even if you pull what you assume may be a better hero.
Disclaimer: If you are leveling Gobbler and pull Caedmon, depending on how far Gobbler is and you ascension material situation, you may seriously consider switching to Caedmon.
But for the most part work on 3-4 solid teams of rainbow 3*, then you can consider moving on to 4*. Whatever you do, do NOT immediately begin working on a 5*. You will waste time, materials, food that would give you 3 fully maxed 4*. So until you have several (I’d suggest 4-5 fully leveled teams of 4*) don’t start those 5*. They will patiently wait in your roster for their time.
Your 3&4* will help you gather the necessary AM’s to level the 5*. Plus the 4* are really the core of E&P, some are very strong and will be with you for a very long time, like Rigard, BoldTusk, Kiril, Proteus, Wilbur, etc
Good Luck on your quest for power!! May RNGesus smile upon you!!