Yep, I know some like to put a huge engine on a plane . They often comment "That is what throttles are for". This is true.
On the other hand , having a plane with less power even marginal power can really sharpen flying skills. It teaches people to fly on the wing, manage speed and altitude . Learning to fly without having the option of slamming the throttle forward after making a sloppy move can be quite benficial. Not to mention the fact smaller engines are generally lighter and the power pulses less stressful on the airframe.

So long as you can get by without trying to impress others at the field boring holes in the sky with limitless vertical and are not in to 3D. If you really want to learn scale like flying , having a smaller engine can teach a lot. And burn less fuel at times .

It is amazing how many of today's RC fliers are so inept at actually using the throttle and flying at the low end of the envelope.

If indeed the engine turns out to be far too small or the owner for any reason desires more power, an engine swap can be done at any time.

I'd like to say put it in and try it out ![8D]