You cannot have different amps, or reverbs, or anything, in different snapshots. A preset has certain blocks, and snapshots can only change the on/off setting for those blocks or parameters within those blocks. I'm not sure what you were doing before (presets maybe?) but you didn't have 6 different amps in snapshots on the same preset.
What you can do, and keep in mind this will take a lot of DSP, is have multiple amp blocks in the preset and use snapshots to turn them on/off. I made a preset like this once that had all 3 channels of the SLO, just for fun. But it really takes so much DSP it's not worth it, IMHO.