Some of the best on the market!
I'd be a little afraid of going for 150watts with them; at full charge it's cutting it close 150/8.4 = 17.85 amps so it wouldn't take long before they're being asked for more than 20A; 150/20 = 7.5, so once the batteries reach 3.75 volts they'd be at the CDR (and with the regulator not being 100% efficient, I'm not sure how that plays in).
But they're definitely able to handle 100 watts throughout a charge cycle, assuming they're wired in series.
ETA: assuming wired in series and that the smaug shuts off when the batteries reach 3.5V you should be good up to 2*3.5*20 = 140 watts throughout an entire charge cycle. Again I'm not so sure about how regulator efficiency plays into this (whether it anticipates inefficiency and asks for extra power, or just fires a bit low), but you could build in a 15% safety margin and not go above 119 watts.
Maybe you have no intention to go super high, or maybe I've overthought it, but that's how I'd handle such a powerful device

I'll double check that they're in series, as try may not be...
ETA2: sheesh, sorry for the massive post. Anyway, the batteries are in parallel. The results turn out the same, but the math just looks different.