We will have to agree to disagree. Arbitrarily arguing that casters should be allowed to magically muti-task concentration spells because "waaa" is both ridiculous and a gross violation of the current magical system.
The tradition of employing hirelings, henchmen, scaleable companions, and sidekicks are both legacy ways to grow a parties power and productive ways for a DM to assist the players in putting down roots in the campaign world. Things that both videogame and many tabletop roleplaying games seriously lack right now.