Disagree. Done mainly to get car lower to ground, when drag cars started going to them for that as well as the 50-75 or more extra hp they brought. Indy cars use them to get low, low, low. Horsepower there too. All at the time decried how they could easily bring car down since the systems were more complicated. Having to balance scavenge flow to pressure is a whole 'nother thing that has to be right that is a nonexistent problem on wet sump systems. The dry sump tank must be right too, not as simple as just throwing a tank on there. RPM not an issue since same type of basic pump used as in wet sump but with more sections. Running a belt drive dry sump pump outside motor gets more trouble than a pump inside engine, rocks pitch in belt and broken. A regular wet sump pump can go 12000 rpm or more if system designed right and applied right. Not that ALL of them can of course..........but the potential is there.
Dry sump allows stripping away of the oil that stays around crankshaft at higher rpm to sap hp. That's where the extra power comes from. On the 700+ inch motors we used to run it was supposed to be worth 75 hp @ 9000 rpm.