Is my Shimano Deore SLX dérailleur a medium or long cage?
That linked answer is great, but the lengths of derailleur cages have been increasing with successive generations, so those figures are out of date now.

You need to consider the size of largest cog which the derailleur is compatible with and compare the specs of the individual units.

Counterintuitively, the longer cage is actually compatible with the 36 tooth large cog you have, even though this 36 is smaller than many around today. The medium  cage M6000-GS is suitable for cassettes where the largest cog is a 42T, while the long cage M6000-SGS works with cassettes where the largest cog is in the range 32-36 teeth. If you were choosing between these two, then you would choose the SGS long cage

There's every likelihood that your bike currently has the RD-M7000-10-SGS for the same reason (also its the 10 speed one).