Sorry to throw a rock in the water here, but the idea that a single type of aircraft effectively or even marginally addresses Finland's defence needs is pretty slim on evidence. Finland held off the Russians with good pilots, not good planes.

The question is surely best addressed by asking, what does Finland want to do to Russia if it is attacked? What would break Russian will to persist? How casualty sensitive is Russia versus Finland? What about the Baltic States.

In terms of F-18's, capable though they may be, I'd be far more interested in what Tanker and EW aircraft might be in the mix.