I'm actually quite interested in this particular potential 'localisation switch' (i.e. the Turk's presentation), if anyone digs up anything specific let me know.
But yeah, even in the US version, there's definitely still purposeful silliness--talking about who their crushes are on a stakeout, Elena's various blunders, "we're fleeing but we're still victorious"--but it's balanced in a way where it just makes them seem like 3-Dimensional human beings (rather than being pure comedic relief), and, as mentioned above, potentially even more callous towards the severity of their work. I think that whole Wutai sequence ending with Reno's "because it's our job" as he drops Corneo to his death really sums it up. There's a certain 'whimsy', you could say, in the sequence, certainly a flair...but ultimately, a dude just got splattered all over the pavement, and we never forget that.
Being that the RM is not seeking active connection with the Compilation, they have the option of portraying them either way (or a new way entirely). I suppose some of my concern comes from the fact that now Nomura is in CHARGE, and the zany-funny-stylish angle seems to be much more his bag than anybody else's.