Simon Brokaw and the Move West

Just how many Simon Brokaws were there, anyway? I am just getting started finding hard sources to back up the family stories and I am confused already! My grandfather's father Henry Vanderveer Brokaw, was said to be born of Simon Steyker Brokaw in Somerset, NJ 8-1-1854. The Simon Brokaw I find in the 1850 US census is in Nebraska and the family with a Henry in Somerset in 1860 doesn't have any familiar names.

I know there will be a logical explaination when I really get into this, but it feels good to vent.