I remember an interview were Pick said that recording Industrial disease was a painful and non-gratifying experience for him.
And yes, he said that Mark's intention was to put more and more keyboards (1 keyboard for the OL tour, 2 were planned for the LOG tour) and that was diminishing the drums's role and he had had enough...
Pick was brillant on the first 3 albums and the first 2 tours. On the OL tour he seems a bit out of place - with the new, longer version of Sultans, you can hear that it's not his thing, and that Terry would do a much better job in this new stadium area.
Pick was more subtle, Terry was more powerful, both were great, and by the way they are the best of friends today...