If you’re going friction rather than indexed bar end shifter, anything works with anything, with the caveat that you might need to file away some of the shifter holder bit for more room.
I’ve used Silver Shifters AND 8 speed Shimano bar end shifters on anything from 9 speed through to 11 speed cassettes, up to 11-42 size. Both with a 9 speed deore rear mech and a 10 speed XT rear mech.
The beauty of friction is that where the cassettes aren’t any wider, and the rear mechs have loads of travel, there really are no issues.
Regards to the filing, i had to file away about 1/2 a cm of the housing bit (the bit that screws into the handlebar) to get enough range with the 10speed XT mech.