You wouldnt think so would you, other than a mtb crank being a bit longer for 73 mm, but i recently compared a deore xt and a 105 bb and the 105 was a bit slimmer
They usually come with spacers etc so if it kit you have already, worth playing around, but if youre getting all new stuff, id get the right stuff and crack on, not worth the agro of faffing with chainlines and front mechs for a 10quid bb
Also 11 speed shimano on road cassette dont fit on standard mtb hubs, they can only run with 10 speed road cassettes, but they can take 11 speed mtb cassettes. Go figure!
That said tiagra/105/slx/xt groupos are really good value i think, all look and work well, so just get the full set and be done with it and ride the bugger!
