You have visibly a fundamental misunderstanding about mining blocks.
If you have hash power that is so that, with a given difficulty, on average, you find a good block, say, every hour, which means that you have about 1/6 of the total hash power *when the difficulty was determined*, then it doesn't matter whether others are mining or not, you will win, on average, one block every hour - minus those few seconds that you were mining on the wrong block each time.
your not getting it at all!!
ok try this..
imagine the olympics 100m
5 guys.. they all run
average is 10 seconds to get to the other end, and only 1 guy wins
now then, you ask the 5 guys to run the length 6 times..
out of those 6 times there is a guy that only wins once..
does that mean if he was the only runner it would take him 60 seconds.. no
because the game is run for 10 seconds and reset.
all the guys run within milliseconds of each other but there is only one winner, the timings of the other 4 guys per race are not multiples of the first guy, but miliseconds behind the first guy.