I use to jam with a guy who would show-up one day with a Soldano SLO, then a VHT Pitbull, then a Mesa D/R...

To my ears, the SLO (with its top-end sizzle) sat best in the mix. His Pitbull and Rectifier tended to ventured into bass player frequencies; regardless of how he set them. He wouldn't let me dial him in, of course. I asked him to stick to using the SLO, or find a nice blend between two amplifiers...with the SLO as the dominant voice. This was unacceptable to him as well, so he left. I tried to explain the priority of the mix, which didn't make a dent. This is what happens when a guitarist spends too much time playing alone vs playing in a band.