Concordance - The max spell points is what is says in the table for level 20, for each class. No combining seeds. You'd have a total # of points of 11 (Gallant) + 126 (Champion) + 17 (Arcanist), plus whatever bonus points you had, which puts you far behind a pure build. And you couldn't use Gallant spell points for Arcanist spells and vice versa.
Unison - The max spell points is what is says in the table for level 20, for each class. No combining seeds. You'd have a total # of points of 11 (Gallant) + 17 (Arcanist) for spell points, and 126 (Champion) for martial points. And you couldn't use martial points for spells, and vice versa.
There is no cross seeding. Not yet, anyway.
So what this tells me is I might need to take another look at those feat chains again. Because you end up as a kind of crappy all-roounder.