I'm sure that our Tests are not ordered in any special way. The Tests are designed to be more difficult than real GMAT questions. No wonder some questions require more time. Many people here on the forums will confirm that the more you practice the better and faster you solve the problems like the ones in GMAT Club Tests
Hope this helps
Welcome to GMAT Club!
Want to solve GMAT questions on the go? GMAT Club iPhone app will help.
Please read this before posting in GMAT Club Tests forum
Result correlation between real GMAT and GMAT Club Tests
Are GMAT Club Test sets ordered in any way?
Take 15 free tests with questions from GMAT Club, Knewton, Manhattan GMAT, and Veritas.
Get the best GMAT Prep Resources with GMAT Club Premium Membership