https://us.msi.com/Motherboard/970-GAMING.html#hero-specification
Click on "Detail" under the Specifications, then scroll to Internal I/O Connections:
-1 x 4-pin CPU fan connector
-2 x 4-pin system fan connectors
-2 x 3-pin system fan connectors
Heres a link to the manual:
https://us.msi.com/Motherboard/support/970-GAMING.html#down-manual
Check out page 1-20 it will show you all the fan connections.
There is no way in the world a modern ATX motherboard only has 1 case fan connection, even mATX boards have at least 2. Whoever told you that doesn't know what they are talking about.
If you use a splitter anyway you should only split it once, so run 2 fans from 1 header thats it.