I think using the same brand of amp and model supports the same amplifier character which came deliver a more uniform presentation.

My current amp is the Parasound 160+160 model. It’s more neutral than my previous Passlabs X250.5 and delivers what’s in the vinyl grooves better than any amplifier l have used previously.

The problem to my mind is that so called hi end amplifiers often have a house sound to signify or differentiate the brand from another. These boutique brands wax the audiophile ears with what they want to hear “after” they read the Stereophile review praising how nice it sounded.

With loudspeakers as accurate as the JBL monitor it makes sense deploy and accurate amplifier ad opposed to a load of 2nd harmonic “sugar” coated sound.