We used 3 mats and there is not enough room for any more mats. However, by switching to a 3 day tournament, which I have personally experienced with tremendous success, you could counter the space limitations. One class would go with a morning session and the other would wrestle in the late afternoon. This also gives spectators the option of watching the other class if they so choose. In MO they only wrestle the first round on Thursday and every one gets out of the arena at a pretty decent time.

I must preface all of this with the disclaimer that I am not blessed with good looks or a fully functioning brain - so my logic may be way off!