Once they are back at the covenant, Marcellus will make sure the new "recruits" (Isabelle, Bernardo, Ignacio and Julio) are settled in and a job for them is found that fits their capabilities and aspirations. He will also speak with Bernat to make sure the older grog check on them regularly to see how things are going (this should be relatively easy in the case of Bernardo if he becomes a grog). Marcellus will take the time to speak with each of them a few times as well.
Marcellus will certainly spend most of his time with Regulus as his friend recovers from his wounds, so they will certainly catch up on what each has been doing since they've last seen each other. And their plans for coming seasons and years. (We can have a few scenes about that if you like, or keep it abstract.)
I am sure they will also discuss getting together again at some point, this time without the drama of one of them disappearing on the way. (That could be the seed for a follow-up story a year or two later. If that makes it easier, all the better. I'm certainly game for a second part!)
If Regulus is interested in some enchantment that Marcellus could make in the coming years, or knows of some other Bjornaer magi who are looking for something to be crafted for them, they will certainly discuss that. Marcellus is still looking for a first commission.
(I understand and agree with your rationale regarding "smart" and Inventive Genius.)
(Marcellus' stance regarding Parma doesn't go as far as Regulus', but practicality won out and, well, knowing he wouldn't live as long as most magi means he has little patience for waiting. He just doesn't express that position to others, to avoid creating waves. Regulus is an exception to that rule.)