The way to include most fast twitch muscle fibers is to alternate between 10 reps and 4 reps, 10 reps being best to induce growth, and 4 reps teaching your muscle to recruit as many fibers at once as possible, this is why powerlifters are so strong, because they can recruit more muscle fibers at once than bodybuilders, I think the average is only 50% recruitment. This is also why lower rep ranges is best for strength.
True, so you could do 1 rep sets with max load, but it seems 4 reps is what everyone is doing for strength, are you sure the reps doesnt play a part? because I think the nervous system plays a big roll in it aswell, I cant think of any other possible reason why people would do 4 rep sets instead of 1 rep sets.
...Doing a set of 10 before a lower rep set won't make a difference.
BUT doing a set of your 1-2 rep max BEFORE doing a higher rep set WILL make a difference. (i.e. you will be able to lift more weight for that higher rep set than you would have been able to otherwise)