Cross Pollination of Squash and Gourds
Don't worry about separating these plants. The only concern is if you plan to save seed for planting next year. Cross pollination does not affect the current year's fruits--only the seeds. (This might be a concern if, say, you were planning to harvest pumpkin seeds for roasting.) However, if you compost the plants and some of the seeds sprout, you could have some strange gourd/squash mutants growing out of the compost pile! But there's no need to worry about this year's crop.