Loan Consolidation Questions (Direct & Perkins)?

So I recently got out of college and thinking about loan consolidation. I consolidated my Federal Direct Subsidized Stafford Loan a year or so back before the interest increased to 6.8% (While I was still in school). Since that consolidation, I was still in school and accepted another year's worth of Federal Direct Sub Stafford Loan. I also have Perkins Loans.

Would it make sense to consolidate my last year's Direct Fed Sub Stafford Loan to my existing consolidated loans? Should I also consolidate the Federal Direct Loan with it too?

SallieMae: 5.125%

Direct Loan: 6.8%

Federal Perkins: 5%

If I consolidate those three all together, the weighted interest would be 5.375%

Should I leave Perkins Loan out and just reconsolidate my SallieMae with my last year's Direct Federal Sub Loan? This should be then 5.625%

Most likely. But it would have been better to consolidate all the loans at once so as not to incur the origination fee. It's much better to consolidate your loans for a number of reasons. If you get into trouble (or just behind) with your loans, it's better to have one loan instead of a dozen.