Hi and welcome!
You can add a betta and some shrimp to the 10 gal. There will be enough room and as long as there is plants (tall and short) they should leave each other alone. The shrimp will clean the bottom too! Sasami is the aquatics expert here!!
Maybe she will advise better for you. Me, on the other hand, would have no hard choice- I'd get bettas!! lol
You can divide the 10 gal (with a solid color divider) and put 2 bettas in it!
You can add a betta and some shrimp to the 10 gal. There will be enough room and as long as there is plants (tall and short) they should leave each other alone. The shrimp will clean the bottom too! Sasami is the aquatics expert here!!
You can divide the 10 gal (with a solid color divider) and put 2 bettas in it!