Combat Reform

Hi all, I came up against this scenario recently... I was in a 'grind' combat with my opponent & it was evident he was going to beat me. We drew one round & both decided on a combat reform. We rolled off & he went first, moving more of his unit into base-to-base combat, and more of his supporting ranks directly behind...
I obviously wanted the opposite & thought about moving my unit so that only one model would remain in base to base contact. I decided against this as I thought it 'unsportsmanlike', but is there any reason why I could not? What are the rules around combat reforms & base-to-base contact?
Thanks in advance guys