In 01 it took Montoya some time to adapt to the F1 cars but after mid-point he already had Ralf covered. In Germany a race that Ralf won, Montoya was far into the distance and Ralf was not even close (Tortoise beats hare). After a 10 second lead JPMs had a fuel problem during the first pit-stop and then his engine failed. In Brazil, JoV takes Montoya out from a sure victory... JPM was rookie of the year against Kimi and Alonso.
In 02, no one came close to Ferrari but Montoya, that race Ralf won in Malaysia was because Shumi took Montoya out at the start of the race from the front row.
In 03. there was a fight going on in the garage during the european races, Montoya threaten to quit the team because Williams was only focusing on Ralf. Do you remember Monaco that year or Silverstone (his charge through the field). More often than not, JPM would always pass Ralf on track and finish ahead.
In 04, I don't think Ralf was even close ..
You‘re quite right, if you compare Ralf‘s actual results with the ones Montoya might have got if everything had gone to plan, Montoya would have had more wins than Ralf. And the scores on the doors, which already favour Montoya, would look even better for him.
Back to reality, though, the reason we got to the European season in 2003 and Williams were focusing on Ralf, is because Ralf was doing what no Williams driver had done since 1997; having a credible tilt at the title. Patrick Head and Sam Michael believed that if they were going to win the title with anyone, Ralf was the better bet. Going into Silverstone, which was the halfway point, Ralf was in a position where a win could have given him the lead and he was the bookies‘ second favourite behind MSC. Montoya never got into that good a position during his time in F1, and he did not have Ralf "covered" which is why he kicked off. Admittedly Ralf‘s title challenge collapsed with a string of DNFs, mostly the team‘s fault with one or two accidents for good measure.
Montoya was better at hustling for points when the car was bad, but he really struggled to match Ralf when the car was at its best. He managed it from time to time. But in order to challenge for the title in that car he could not have afforded to lose any points to his teammate, and he was never capable of beating Ralf on a consistent basis.