You have very nice systems.
Before trading amps, have you tried moving the speakers closer to the back wall / corners to reinforce the bass?
The ARC and Mac amps are very different. The Mac’s are heavy bass / midrange with a notable lack of detail / treble, and the ARC amp is detailed, with good midrange bloom and realistic bass as is only achieved by a really good tube amp. Especially given all the ARC equipment you own, you must try a ARC amp. I used Pass amps for decades. The first time I put an ARC amp in my system that was the end of my history with solid state amps and Pass (as great as they are). While the bass slam is attenuated, the bass becomes nuanced and realistic. There was no going back for me.
