COMPLAINT & SUGGESTION
The basic premise of the game is fine, but the combat system is lacking.
The basic problem is the click and send each unit system.
This is cumbersome, and slow compared to how fast the AI can release troops.
It also requires you to focus on the units down below, instead of what is going on in the battle.
I would suggest that you use a completely different system:
Option 1 - Have a strategic level battle.
There are a number of games that do with in various forms, and they are typically pretty fun.
In short: you click on 1 base you own, drag it to the connected base you want to attack, and release. The troops then move along the connecting path to reach the new base.
Typically only a portion of the troops move in this games. 50% seems to be common.
You can send a 2nd group from the same bade before the 1st completes the journey, and they can arrive before the first group finishes their battle, improving the odds of success, and reducing losses.
Typically the regeneration of troops happens in any owned base, and is dependent on the base's value, or the number of troops there. (Or both)
Option 2: Allow the player to set the formation before battle starts, then the troops move forward to capture the objective, fighting the prearranged NPC forces.
I have seen systems similar to what you tried to do, but they typically have hot keys for either the unit type, or the lanes. I've not found any that I felt were "good", but I've found some that were "good enough to tolerate" for the sake of the combat system inside a grander game. It takes a lot of "other stuff" to prop up a bad combat system, and they will never become "memorable classics" like Sonny 1&2.