Adobe Stock Contributor can run two accounts on the same device and the same internet.

The correct information is: sure, that is allowed. The requirement is to have 2 distinct persons to contribute:

1. own Adobe ID - that implies that there are 2 distinct e-mails, as the Adobe ID is the e-mail.
2. own mobile phone number for account verification.
3. own tax form submitted. BTW: submitting wrong data on the tax form may constitute fraud.
4. own payout account. It seems that Adobe requires every contributor to have an own payout account.
5. own assets to submit. If you mix-up your assets (and submit some assets as duplicates) you may experience blocking. 

BTW: this question comes up regularily, and it seems that many brothers, sisters, mothers, fathers, grandparents... want to contribute using the same computer. If it is a cover up to overcome account submission limits, forget about it. At some point, you will make a crucial error and then you will cry. 

To handle accidental asset mixing, I would suggest to set-up own user profiles to sign-in on the local computer. If everyone keeps it's data in their own profile, mixing up data will be less probable.