Drums or rather percussion is a bit special. Percussion channels on General MIDI are hardcoded to be at channel 10 (or 9 is you start from channel 0 instead of 1) so it isn't just a general choice but rather a requirement. It also works a bit differently with its notes: Instead to play a sample of an instrument of a different pitch, a percussion channel changes the instrument entirely and doesn't control the pitch anymore. That means, some note plays a snare and another other one plays a cymbal.
A drum channel doesn't exist on the DSP, SPC700 or the N-SPC music engine (of which AMK's music engine is a modified one) ‒ all channels can play any sample at any pitch (at least how much the console can output). This also means, neither the DSP nor the SPC700 know which sample is a percussion sample or non-percussion (the game's music engine is programmable, though, but we talk about AMK which doesn't do that).
As such, you can tune a percussion sample to play at any note but o4c as the base pitch is still preferrable.