My husband does not train my Schutzhund dog(s) (or any of my sport dogs, really, whether it's SchH or agility, flyball, etc). He can of course do basic obedience or whatever commands are necessary to get them to obey around the house, go for a walk, go in and out of the house. You should both be involved in the basic obedience, house manners, crate training, potty training. Beyond that I don't "share" my dogs so I can't say whether it works or is confusing but I don't think it's very common.
Liesje & pack
Coke (All-American 7/7/06) couch warmer extraordinaire
Nikon (GSD 9/7/08) U-CH SG SCHH1 KKL1 T1 FO PA TFE-II FDCh-S CL1-R UJJ U-CA HIT TT CGC
Indy (All-American 5/10/12) flyball star in training
Legend (GSD 10/22/13) the legacy continues...
Rainbow Bridge Kenya (GSD) U-CH FO OB1 CL1-R CL1-F RA HIT TDI TT CGC