Can't tell from the photo. Smaller bush vine like crooknecks will grow 2 in a hill with hills two feet apart. Most zucchini are much bigger plants and need more room. Of course with vining squash, two plants would take your whole area. If they show effects of crowding just snip off some of the weaker vines.

I used to do 1 zucchini and 1 crook necked yellow squash, but it was way more than the 2 of us could consume, even when zipping them up in a blender to freeze for soup stock!

Even 1 zuk for the 2 of us is already overwhelming!

BTW, August 8th is leave a zucchini on your neighbors' porch day! Just sayin!

Hard to tell from photo how many plants are in there but your sensing is probably right. Better to sacrifice a few to get good growth on the ones you keep and start building your compost!

I think you are going to like the results of gardening in the ground so much better than in pots. It is easier to keep things evenly watered, you usually need to water less often, more minerals probably will be available to your plants, and your plants will be able to stretch out their roots. 😉

Be prepared to pick up growing vines and aim them away from your peppers and tomatoes.