Yup, you got it.
The reason why they aren't all the same plug is because this is a common board design to accommodate a range of configurations. It can do as little as 3s (maybe 4s) all the way up to 20s. The only thing that is different in how much of the board is populated with components. So if you wanted to change this board, you could just alter what is connected on the board.
Make sure you connect your balanced leads in order. So start with 1 and go to 14. If you have no cells in the packs when you do this, it's not an issue. But always try to power the board from the first pack first. This will help ensure you don't accidentally blow anything off the board.
I've had a bms get fried because one of the of the middle leads came loose of the bread board while i was working on it.