I think the problem is that there is very little scientific evidence to support the use of sprouted grains in poultry. In fact, there is very little scientific evidence to support benefits of sprouted grain in the human model either. One one hand, you can't say the first chart of this study supports growing fodder since you are correct, chickens have crops, not stomachs. We need to see data on how it is absorbed by the crop.
If people want to grow some greens, I have no issue with that. However people are talking about total feed replacement and lower feed costs without anything other than anecdotal stories. That can be dangerous to the lives of a new flock owner who doesn't know any better. I have a friend with 150 birds that is investing significant time and financial resources to start growing fodder for his flock to replace all commercial feed without any real analysis. As a greens supplement, it may make sense if you have the time and energy and potentially more money than you are spending on feed now to invest. I think it's important to scrutinize things. At this point, it seems like the scientific jury is still out on what fodder can offer your flock as far as actual benefits (feed replacement etc)
It would be nice to see a poultry-related comparison for sure, as I would LOVE to do away with commercial feeds or - at the very least - limit commercial feed to a minimum for supplemental purposes.