Bryston 3b or adcom 100wpc for center & main

I have a HK 635 with infinity crescendos for mains,thiel center and mirage surrounds with svs powered sub.The surrounds are powered by an adcom GFA 2535.My question is do I power the mains with the bryston or put it in mono for the center and use the adcom 100wpc for the main?
If the impedance of your Thiel center is much less below 8 ohms, then neither amp should be bridged as a monoblock.
Would there be an advantage to using a stand alone amp for thye center channel instead of the internal amp in the HK? I had been using a sony amp in mono mode in the past without a problem.
Mixing 3 amp brands and 3 speaker brands is not a good idea. Consider selling your least favorite amps and speakers and start building a proper system with matching speakers and amps. Start with the center or L&R speakers.