There should be more normal elixer troops. Maybe even if you could do something like making a group of cavalry units in one press of a button but they cant take up too much space in the camp. But there shouldnt be only one type of cavalry, there should be one like archer cavalry. Anouther troops could be the artilery squad, they work an artillery cannaon and shell enemy defenses from safty(or if too overpowerd they cant have a range greater then the archer tower.
There should also be some more heroes like giant king, Barbarian queen who supports and follows the barbarian king and all barbarians in battle and the dragon whisperer who summons and supports dragons in battle.