Mhalir is so proud of her! He doesn't say this, she still seems untrusting about that sort of thing, but it leaks through clearly when he talks to her.
Also he's delighted to be back in her head. The temporary host he borrowed was at least semi-voluntary and cooperative, but wasn't nearly as smart as Carissa-plus-magic-items.
He's ready to meet with their new recruits, them around the workshop for magic items, hand them computer tablets and show off their other technology. And then carefully explain more about the war situation, let them cast Detect Thoughts on him if they want (while he steers his thoughts toward some topics and away from others).
After that he brings up the topic of matching them up with Yeerks; like with Carissa, he frames it as a very collaborative sort of thing. Which doesn't even feel like a lie, after his recent weeks of working with her. He doesn't have any systematic way of selecting Yeerk-host pairs for compatibility, but he knows most of his personnel very well, including the Yeerks brought in the pool without hosts in case prisoners were taken, and he can describe their personalities and let them pick, and of course they're welcome to swap around if it doesn't work well.