coin counter #1 and coin counter #2 are for coin switch #1 and coin switch #2.
I gather what you are asking is maybe how to get both coin switch counts to the same counter? if so, I think you could put both coin counter wires on the same terminal, and then hook ground to the other on your counter.
all the coin counter wires do is feed an output pulse to flip the digits in the counter. all you would be doing in this case is wiring up 2 outputs to the same source (the counter itself).
an alternative approach, you could do away with the wiring for coin switch #2, and just piggyback the coin switch #1 wiring from say, the right coin switch to the left one. then you just run coin counter #1's wire to the one counter terminal and a ground wire to the other.