The Rec and Uber have been there a while… the other spot (the the Archon is in) was originally a Bogner Shiva, then a Two Rock CRS, then a Bludotone, and now the Archon. Those other amps were always used for leads to bring a bit more mids to the mix, so I can only assume he's using the Archon for the same purpose.
If all is as it seems, that's a pretty impressive lineage for the Archon to pick up from...