Watts mean very little in this respect, max wattage ratings on speakers are more about melting points than anything really useful. Use sensitivity specs if you want to compare how much amp power is needed for a given spl (sound pressure level). Use an
spl calculator perhaps to help see the relationship of watts to spl.
Capable to me is more about frequency range and spl capabilities. I'd use the speaker with the lesser frequency range spec and smallest drivers for rear surrounds and just the opposite for my main L/R speakers, those I want to be the most capable.
ps Just googled each of your speakers briefly, not a lot of info there but see you have mostly floorstanders there. Are you raising the surrounds up or leaving them on the floor? I'd use the smallest drivers for rear surrounds. Are you going without a center?