Sounds like Kaltenborn actually signed with Mercedes, Ferrari and Renault too, and Honda is finding that out only now
Anyway, i think a Merc engine would do a whole lot of good for Sauber. Just concider; last year's Ferrari engine is worthless vs the rest of the field, an is only marginally able to compete with a complete shamble of a honda engine and it seems that Honda has passed that too by now. Have a current-spec Mercedes in there and we're talking a different story here, i think on the technical side, aero remains to be seen though, they could possibly compete with Renault. Offcourse Hulkenberg is too big of a fish but Palmer? well, no problem there.
So a Mercedes engine would do wonders, thing is though, are they able to afford that AND have a decent aero, including development during the year? Wehrlein is a benefit as he'll bring in surely some form of discount (or are old ferrari engines still so much cheaper?) and he's a merc protogé so guaranteed feedback and help from the mothership team. There's still the problem of ericsson, but well, you have that too with an old ferrari engine.
sounds to me like the longbow boys have upset / read insulted the Honda high ups. bad decision.
I wonder what longbow really is, to be honest. i've never taken time to investigate. is Sauber over before the end of the year?