I think that you are a bit confused.
There are 6 oil seals, if these fail, oil will leak into the spark plug chambers.
There are 2 rubber gaskets, if these fail, oil will only leak externally and not into the chambers, however they should be replaced every time that you remove the cam cover.
It is also worth mentioning that if you replace the 6 seals, you should also consider replacing the 6 spark plug tubes.