I'm not sophisticated enough to know for sure, but I wouldn't give that much extra credit for airplane hours. For example, if I thought that 500 helicopter hours was sufficient to entrust my life to someone, I wouldn't take someone with 300, just because he had 200 (or even 300 or 400) hours flying a completely different type of craft.

If it were going in the other direction, I might be more likely to be accommodating, since my sense is that helicopters are harder to master than airplanes. But I'm no expert here, and I would definitely ask around to see if my understanding is correct.

If I were to say combined 5 years of professional experience in rust + C++, employers would definitely want to see the breakdown, unless they really don't care if it's 0+5.

(And in the case of my claim, it is indeed 0+5)

I think there’s a certain point at which you are considered safe to fly by yourself? Most commercial pilots seem to have hundreds to thousands of hours of combined flying time.