Some changes or restrictions
Allowed spaces for landing troops can be outside the boundaries of the base and not over the base in order to avoid unnecessary advantage to the attacker or else attacker will go for core and an easy 1 star is at the doorsteps. Spell can be small in radius as well e.g. 3.5 tiles, to avoid transfer of a lot of troops from one place to another. Spell timings can be 3 seconds or else the spell will be considered used and failed. Upgrades can include more time to use the spell and increase in the width of spell by 0.5 tiles every upgrade occurs. Spell can be unable to move heroes but can move defending CC troops along with your attacking troops.
Any other suggestions are highly appreciated. Kindly give a serious look to it SC.