Charles certainly wasn't doing it for himself; his resume was impeccable.
If he wanted, he could even become a real salary thief, as his legally defined boss, the Crown Prince of the Fars Empire, never interfered with the affairs of the Patrolling Army. Whether he went to work or not didn't affect the salary distribution; he was doing it to secure "positions" for that group of adventurers.
Since he had been forced to flee, Charles had resolved to do something significant.
Once he turned this group of adventurers into the Patrolling Army, he wouldn't just be a mere commander.
As for the adventurers, there was no need to worry.
The Patrolling Army was an official military position. Although the income of the lower ranks was meager, it was stable and safer. People generally wouldn't attack members of the Patrolling Army. Their lives were much more settled than those of adventurers.