Another issue has popped into my head which might be obvious, or might be worth mentioning. If you drop out of your current very good LAC and instead go to community college, it might look to some people as if you just could not handle the tough course load at your current school. Williams is one of the very top ranked LACs in the USA. Why would they want to accept a student who could not handle the course load at a slightly lower ranked LAC?
Of course this is not your actual reason, but it might be something that admissions at Williams would wonder about.
Again, do as well as you can at your current school. If you have to transfer, then apply directly to schools that you would intend to stay at for a full four years until they hand you a bachelor’s degree.