Haha!!! That's too cute!
Casey, my tiel, used to interact with a flock of budgies. The budgies weren't particularly tame and friendly with me, but they'd sit with me if I wanted them to. I recall one time when I was scritching Casey's head and she was so into it that she didn't notice that one of the budgies, curious creatures as they are, "sneak up" on her and started preening her head, too! Boy, was she furious when she realized it wasn't me!
My mitred conure also enjoys preening other birds [*IF* I'm holding them - doesn't care for them otherwise!], but none of my other birds like him, so that doesn't go over too well and I keep them separated.
Sounds like you've got a great "pair" that gives you both sides of the spectrum!