Your third ability will always lag behind the first by several levels, because 1st, 2nd and 3rd abilities each take progressively longer to level-up.
My pet for example is 90/86/72.
After you fuse, your third ability does still rocket up pretty quickly, you’ll be looking at numbers like:
72/67/33
75/73/46
80/77/56
85/81/64
90/84/71, and 90 is the cap for this tier, so any more feeding will only raise 2nd/3rd abilities.
-source
So you have to decide how important 3rd ability (mheal) is to you, because it will always be a bit lower. If you’re happy with this, then go for it. I personally find that 70-80 mheal is “enough”, I feel like I can’t press space fast enough on some classes, and on ones like warrior I literally can’t because of the cooldown.
If you had heal as 3rd, I would have said definitely keep hatching because heal will save your life, mheal is only extra OP spammage. But as you can see from the numbers above, 2nd ability is always close to 1st, so you aren’t screwing yourself by having heal 2nd.
(I can’t comment on electric ability in itself, as I’ve only gone to 50 with elec)