Shevchenko and Kezman were silvestre type signings? Seriously? Come on man, Kezman came with a similar CV to Chamakh and Shevchenko came straight into the first eleven.
Squillaci is comparable to the defenders that I mentioned but then you could also look at Glen Johnson, Jerk off, Bridge, Bosingwa etc.
Point is that they go through players like no tomorrow; that is a luxury that they have had since Abramovich bought them. They have the capacity to make mistakes in the market that pretty much no other team has been able to in the last seven years.