It depends on the impedance profile of each speaker to an extent, your amp's capability to deal with such as well as overall your spl (sound pressure level) requirements at your seat in your room; maybe
try an spl calculator to get an idea of your needs. Hard to know if you'd benefit from an external amp but your receiver doesn't have pre-outs for such an amp anyhoo (only has subwoofer preouts), so you'd need a different avr/pre-amp to use an external amp for your speakers.
Easiest thing to do is hook it all up, calibrate with YPAO and sit back and enjoy it, if it can't get loud enough without distortion/clipping then maybe you need to do some more shopping, but otherwise just enjoy....