Below average was an exaggeration.
Overall though I do think merely decent slip fielders are good enough in the vast majority of circumstances. When there are 3-4 slips packed in, the majority of chances that go to guys at first and second slip aren't going to be that difficult. Shane Warne, for example, is someone who I'd classify as merely pretty good rather than anywhere close to the Waugh tier and Australia managed just fine because of the number of chances their bowlers created.
An elite cordon turning half chances into wickets obviously provides that extra something that raises a team's ceiling, but that benefit is less than the detriment to a team caused by a poor cordon like Pakistan's.
We've had this conversation before, so wouldn't drag it out.
I don't think that merely decent cuts it, the same way merely decent cuts it for the batting or bowling if you want to be a great team.
The easiest catches normally go to first slip (with the degree of difficulty generally increasing as you go out), plus the can be protected to a limited degree by a great keeper and or 2nd slip. And yes, Shane was somewhere between ordinary, decent and good, but was surrounded by excellent to superb. Plus when Hayden replaced him for that one year, the standard was drastically improved.
And yes, it was made easier by the number of chances that great attack created, but what if they didn't have such a good attack or faced stronger opposition. Basically the same argument you use when I say that the great Aussie and WI teams didn't have or needed a great no. 8.
And yes the ability to take half chances and blinders does raise a team's ceiling, and similarly a poor one dooms a team to mediocrity.
Just saying it's more important than many gives it credit for.
