Can I stop two factor-authentication from sending a code to my other devices and just text me a code?

No, do not sign the other iPhones into the same Apple ID. Apple IDs should not be shared at all.

If the other people in the group are using the iPads, the iPads should be signed in to their own Apple ID and not a common one.

You can setup the phone numbers from the other iPhones as trusted phone numbers to get an SMS or a voice Call on them with the code if that is what you want. Though I don't think that's it.

You cannot stop the other trusted devices from also getting the code at the same time however. Trusted devices should be used by one person only.

If the other devices are not used by the same person, then they should not be using the same Apple. ID at all.

If these are company owned devices, they should be managed so each person can use their own Apple ID. And each person gets their own 2 factor authentication code on the devices they use.

Apple Configurator can help you Manage devices so each person can use their own Apple IDs on them, and you can wipe them when they are returned.

Link-> What's new in Apple Configurator - Apple Support

If the devices are all signed into the same Apple ID/iCloud account, they are all trusted devices and they should all get the code and you should not have to do anything. I have four trusted devices and when I receive a code it goes to all four devices.

If they are all signed into the same ID, you cannot change how the codes will come to each or any of the devices.

Phil0124 has given you a very informative post with excellent advice. Follow those instructions.

I was under the impression that all of the delves were sharing an Apple ID and that’s why you were getting codes on all of the devices. I apologize if if I misunderstood.