The Bishop still gets my vote for two articulable reasons. First, the road wheels on the Russian tank match. The mis-matched road wheels on the Bishop (as on most of the tanks of the series) give it a 'thrown together' look that is missing from the Russian machine. Second, the armored box on top is so grossly disproportionate to the bottom on the Bishop. The Russian tank has a certain funtional ugliness, but Bishop lacks utilitarian elegance.
Yeah it looks like they found out they didn't have enoough of the same size road wheels to put the Bishop together and found some "spares" that would fit.