is this for use against ai and players?
in that case it would be a detriment (hehe) to your skill as a player.
as the battle progresses the units you will need are very different from moment to moment, limiting yourself to 5 thugs and 5 roughes at all times (example) is likely going to cause you to lose most fights. it is predictable, inflexible and inefficient.
you could argue that you can change the units and amounts you want, but this you can do by looking at the battlefield and building the units you need in that moment.
going back to configure a widget everytime you need diffrent army compositions sounds like a wonderbard apm sink, you should learn to make use of the factory hotkeys and stay ahead of the opponents army in couter ability
basicaly you re cutting on the time it takes to queue an army (seconds?) and adding to the time it takes to respond to your opponents army, which is quite often already taking too long (acquiring intel, building counter, moving into place, striking)

yours truly the dream catcher