Superior Prowess
Many combatants in Arx had been itching for a fierce battle for a while. The Untamed Army trained tirelessly for weeks without taking any big breaks to rest. They did the bare minimum to allow their mind and body to recuperate just enough to generate the most benefits from training. Other than that, they trained tirelessly since they'd been summoned a few weeks ago.
The Combat Summons desired to leave the training ground and show everyone how much stronger they had become in the last few weeks. They wanted to show Michael that they were strong enough to face their opponents head-on and that it was time for them to gather more real experience on the battlefield.
Michael didn't like that, at first, but he sensed the perfect opportunity to give the Combat Summons what they wanted.
In the first place, most new Combat Summons were Berserkers and Warlock Centaurs. Of course, they desired to jump straight onto the battlefield.