I’m generally a SRAM fan, but there’s no reason you can’t run a SRAM cassette and Shimano shifting gear although you obviously need the XD driver freehub.
I did a bit of a dig though, and you can put together some very competitive hybrid groups :
GX 1x11RD, X1 shifter, XG1150 cassette, 30mm BSA BB, Next SL crank, Absolute Black 32t oval: £559.05 and 1374g.
GX 1x11RD, X1 shifter, XG1150 cassette, 30mm BSA BB, Turbine cinch crank, AB 32t oval: £424.05 and 1559g
The BB and ring are 149g and in the Next SL based group I’ve given, adding them to your XTR hybrid results in almost an identical weight (ok, about +25g for the SRAM stuff)
I’ve priced cranks at CRC and the rest at Winstanleys.
The 10-42 XG1150 cassette is all 4130 chromo (even the big cog) and is 394g. The M8000 11-46 is 434g… If you’re using the lowest ratio a lot the SRAM cassette should outlast the XT by a way, I’d think owing to being all steel. This group (with the Turbines not the Next) is what I’m running on my Solaris and the basic drivetrain combo is pretty much my standard now. I don’t think you can really beat it for price, weight and versatility. You’d probably be wanting to factor in a bigger front ring with the Shimano group, too – which could be getting close to chainstays and will obviously be heavier.