Boyd, in PF:MAD, gives Botkin no clear role in his interpretation. At several points, Boyd uses the locution "stands behind" to describe Botkin's relation to Kinbote. But he does not appear to acknowledge that this phrase needs a good bit of unpacking.

JM: Quite often Nabokov suggests a homosexual link when he mentions "letters standing in queue like soldiers in a line," aso. 
The locution "stands behind" and the inverted letters (Kinbote/Botkin) could it bear  a similar intention on VN's part?