By stating, 'Have 2 accounts on each.' it's not quite clear if you have two email accounts running concurrently on both the default email app and the Gmail app, or you have four email accounts with two on the default email app and two on the Gmail app.
-- If it's a matter where you do have just two email accounts running simultaneously on both email apps, than just disabling the default email app will take care of the matter.
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-- But if you have four different email accounts split between the two email apps, in that default email app you should go into its Settings menu, access the config info, and use that to add those two email accounts to the Gmail app (so all four email accounts are on the Gmail app). Then disable that default email app.