A very realistic concern that all of us share.
Some players do very well. Some do not. There is no tool we can use to be sure about anything, but there is no tool that say Syndergaard or deGrom will earnt their pay, either. Sure, we seem to know what they can and might so, if healthy by a wider margin than we know about Yoshida, but there is risk with every signing.
Looking at his numbers in Japan, one could say he's worth twice what we paid for him. We paid him half, because of the risk. Maybe, we could have gotten him for a third. Maybe, it's probable we could have.
If he works out, I won't be bothered by the "outbid." If he sucks, I'll blast the move like I did the JBJ, Diekman and other deals I disliked from day one and those I came to dislike in hindsight. There are plenty. There will likely be more. Maybe this one- maybe not.