I have to start work within a month or two of hearing a response. Thus, I commence this work with students who are here. This system does not lend well to long term recruiting. There is no formula. If I recommond you, you will get a high priority for an RA in my group later.
Most students find support within a few months.
At worst, you are eligible to co-op after 9 months. It's stressful but most cope OK and the outcome is well worth it. You are still better off here than with a TA at lower ranked University.