I know it is a jerk thing to say also, But have you considered diversifying your tank group a little more? Right now my guild has Me(Frost DW) and Druid as our main tanks, we also have 2 warriors that are about 1/2 tier worth of gear behind me and the druid (we are the progression tanks for 25). We also have at least 1 other frost DK about a full tier behind, and a paladin keeping up on his own accord (he plays with the azns in our guild and does 25's with them).
But I suppose my point is that we have found rolling with a lot of the same types of tank at the same time can highly limit your options, and if that is all you have to work with then your warriors have to find a way to make it happen. (we have very little issue with our warriors, we let them handle stuff they can single target tank.) If they can't, it may be time to see if anyone has a desire to tank, or find you a Druid/DK to take one of those warrior spots.
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