Rubu, throwing some stats without proper analysis can be very misleading. Let us look how some of our senior batsmen have done against Zim as opposed to their overall career-
|Batsman||Career Avg||Against Zim|
As you can see all of them except Ashraful has a much higher average against Zimbabwe.
About Rana, when you take out his scores against Zim, his average comes down to 17.76 as opposed to his career average 20.68. SN's average comes down to 22.87 (as opposed to his career average 39.74) when you take away his scores against Zim, Kenya, and Scotland.