Research plan for a first-time faculty application
I see from comments that the interview is past, but here's still some thoughts on this that might be useful for someone else.

I would say that your results at a 3-years horizon don't depend that much on funding prospects, mainly because you're not starting with those funds from day 1, and as a new lecturer you're certainly not expected to have an army of postdocs working for you in the first couple of years. 

You might spend a few months writing the grant proposal, then the process will take some more months, and then from decision to start date there's more time... so assuming success you might be able to hire someone to start in a year at best, more realistically two. Then would you start immediately with postdocs? Unless you're one of several investigators in a larger project, that doesn't sound realistic. Rather you'll probably be supervising MSc projects, and you might hope for one or two PhD students to start within those three years, and with any luck get their first paper or two. I think what you need to pitch is a set of ideas that could form a grant proposal and some realistic-sounding MSc and PhD topics.

The bottom line is that you're being asked for a 3-year plan to see whether you can actually prepare a plan that involves medium- to long-term goals, rather than just think of the next development of what you're doing at the moment.