More than one account

Hello,
I have Meta Mask installed in both Chrome and Brave (not sure if I should) and when I log in I have more than one account (ETH mainnet). How did this happened?

Can I consolidate/merge them in just one?
Or transfer all my balance to just one?

In Chrome I have 3 accounts:
On the 1st I have a very small amount of ETH, some NMR and LINK.
The 2nd is completed empty.
On the 3rd I have a very small amount of ETH, some LINK and cDAI.

In Brave I have 2 accounts:
On the 1st I have the same coins and amount that the 1st account in Chrome.
The 2nd I have the same coins and amount that the 3rd account in Chrome.

Doesn’t make sense.
Can someone help me understand this?
Thank you so much.
Cheers