Even when William left the leadership of his team over to Thomas. And frankly speaking, their overall help wasn't that much to begin with compared with other teams.
But right now, William stated it clear that he'd be the one leading the yet to come battle.
"You are going to use your thing," William didn't say much, "and with it, you can see if these groups have others behind that we didn't discover."
Thomas got what William wanted him to do, "after that, you'll keep using your thing all the time, discovering the current whereabouts of other dark spirit masters hiding behind."
That was part of the reasons behind William's patience. He wanted more vanguard teams to be here so Thomas would detect much more. William knew if he just depended on his array, then things would be difficult. And if he laid in wait for the dark spirit masters to finalise their trap, then things would be more difficult.
