I'm going to pull a you and hit you with some numbers lol.
The Raw before the Rumble where Orton punted Vince drew a 3.87 and the Raw after a 3.6. The next two weeks got 3.59 and 3.42. The Feb 16th show where HHH got involved got a 4.1 and so did the next week. Then things stayed between 3.6 and 3.8 for the rest of the time until Mania. Don't have anything on any of the overruns but I'm pretty sure all the big segments (Orton punting Vince, HHH coming out, Orton handcuffing HHH and kissing Steph) drew big numbers iirc. That Orton/McMahons/HHH program did really good business for them it seems and was a hot feud.
This, and the bold part is the meat of it. It did really well because it was a "hot" angle. It was interesting, it had the McMahons (and those always draw well), it had HHH (who's a draw himself), and then it had Orton, who was the sun to all the planets (people) in the solar system (angle). But that angle didn't draw well because of Orton necessarily, but it was great booking, interesting stuff happening, and all the draws that were around him.
Like I said, I'm not saying Orton isn't a draw, but using that angle isn't the best indicator of him being a draw. There were so many other factors to it outside of Orton himself.
Edit: That 3SOH match was just... ugh. There were so many things wrong with it. Orton came out looking so weak, even though he retained the WWE Title. The match itself was just trash from what I remember, and yeah, the fact they waited until then to let them beat the shit out of eachother when that should've been at Mania was just stupidity at it's finest.