Obviously it gets more difficult
Lets look at the progression if the offense completes a pass.
R-2 and R-3 should not chase the disc, but instead shift back to prevent continuations
Like so
In fact, the only people who mark are R-6 and R-7, so note that as a defender, you are not guarding a man, but you are manned up on a person in a certain position sometimes (i.e. handlers and front of stack).
To preserve defensive integrity, shift the scheme back.
Once again, we must reorganize when possible. Never guard space that is not yours to guard (i.e. marking when you are 1-5).