I think Canadian banks are long term holds that shouldn't really be flip-flopped around in a portfolio.
That said, I did trim some of my Canadian banks at the end of the year because of the strong runup they had. This wasn't really an element of attempting to time the market but more so because my financials inside my portfolio had such a strong run I was at the point where I was over-allocated and needed to rebalance.
You are on the right thinking path in terms of small and mid cap companies. They do stand to benefit from Trump policies that are very much intended to increase domestic production and boost the economy. We can look to a holding I own and a Bull List stock in Alaris Equity. This is a company that invests heavily in private US companies that are set to benefit from Trump's policies and as a result it has posted some very solid returns over the last while.
I believe your thought process of grabbing US small and mid cap exposure is accurate. However, I'm not so sure about selling off blue-chip Canadian institutions in order to do so.