Jos definitely better......

I agree with you. Jos has been better in the first four races.

Hawever, I don't think there have been so much difference as you try to demonstrate.

In Australia Jos made a great start ( I recognize He's one of the best at startings )
and could overtake Pedro before the first curve. But both Arrows started really well doing several overtakes to other cars. Pedro was approaching Jos when both cars prematurely broke ( before ten laps ... ).

In Brazil Jos was third only because his competitors entered before him for the pit stop. His real place was sixth and in the second half of the race he dropped to the eighth place finishing just about ten seconds ahead of Pedro ( not a great difference for a whole race in which Pedro suffered from gear problems at the end of the race ).

In Silverstone you must be joking if you think Jos was doing a better race than Pedro.
There were such a difference in the grid that
any comparison is unworthy. But think about this : just when Jos needed one of his best starts he lost one place.

On the other hand, have you realized Jos's car always break before Pedro's one. I think last year Pedro learned not to push to much in races the Arrows because it was the only way to finish a race. Jos is so agressive that he is always forcing the car to the limit, wich is not a good idea with a not reliable car.

Let's wait following GPs and compare the performance of both pilots when the car can finish a race.