First of all, the way we play, everyone floats. Except for Pirlo apparently. But the other 4 midfielders float around.
And depending on who is behind Lampard, it doesn't bother me.
Kries clearly prefers the floating mid field approach. Last game though Calle mostly stayed locked in the wing and it worked well with Angelino. For the most part I'd rather see them play more traditional wing roles working as pairs Angelino/Calle and Iraola/Mix on overlaps. In year one with some many new players more defined roles just seems safer until these guys get used to each other. Kries can switch back to the float style next year after all these guys get a full training camp together.