Yep, BBS is right. You’ll get chain growth on a full suss bike, and with the extra chain needed for 2×10 added in, it’ll be pretty hard on the Zee. It’s probably just about possible, but the right way to do it is to get a mid-length clutch mech, and the SLX is pretty much perfect for this. Looking at prices on CRC, there’s about a quid’s difference in price.
Many, many, many moons ago, when I were a student, and top end bikes still came with rigid forks, I used to replace knackered rear MTB mechs with 105 short cage road mechs, mostly because they were about half the price. These just about worked if you were careful about matching front and rear shifting so as not to leave too much slack or take in too much chain, but adding in chain growth from a full suspension back end will make for either a too short or a too long chain.
So, word to the wise: go for a mid cage clutch mech. It will save you a lot of grief in the long run, even if it doesn’t have Zee written on it.
BTW, I have a FR Zee rear mech on a hardtail – it copes OK with a wide range 10sp cassette and a single ring. Wouldn’t want it to have to handle a cross chained 2×10 on the same bike.
