I'd go for Cavani myself, if he's fit.
But I'd obviously take Ronaldo over both Rashford and Sancho, sure. Might even take him over Greenwood - but let's be realistic here: if Greenwood starts per default up front, his goals total will increase. His goals per ninety (minus penalties) ratio isn't miles off Ronaldo's.
Anyway, just looking at numbers is rather pointless. If Ronaldo hadn't joined us, we wouldn't automatically have been 14 goals worse off at this stage - it should be unnecessary to point out, but football doesn't work that way.