Pumpkins don't need a male and female plant to produce fruit. One plant has both flower types on it, so lack of another pumpkin plant that it can pollinate it won't affect production. That said, more flowers blooming at the same time should ensure better pollination but I don't think it will matter very much. Good pollination is based mainly on the presence of bees.

Thanks for your response. I knew that just one plant would produce a pumpkin because of its male and female flowers. It also makes sense that more flowers mean more fruit. I think I'll just mix the seeds by size and let them have fun! I've done this with the preschool using Connecticut Field pumpkins for a few years now but this is the first time I've had extras of other types.