In my opinion, the main problem is that hill has now become a 'hill sprint' stat, it is a stat for hard uphill efforts over a short amount of time and it actually is a very good idea to have a stat like this, some riders (Ullisi springs to mind) can sprint very fast on a hill at the end of a flatish stage. The problem is that the mountain stat cannot be used for the short hills throughout the race before that - fleche wallonne is nothing like a multi mountain stage, even if they both finished on the Mur Du Huy!
The main difference is that puncheurs need to be able to main short, sharp efforts, no more than 1 or 2 minutes and sometimes even less, before descending, recovering and making another effort up the next hill, as well as being able to react when the peloton surges and bunches up with attacks and corners. Climbers on the other hand, need to be able to make an effort which might be up to an hour long or even more, they don't get much of a chance to recover as the effort is very consistent (aside from the occasional surge or attack and the sprint at the end, but your hill stat covers that now). The problem is that they are so different that they cannot be treated as the same thing just because they are both uphill. And the current method leads to a pure climber being stronger and getting less fatigued by the first 200km of Fleche Wallone than a pure puncheur.
I have a couple suggestions on the best way to fix this in general: The first is to simply embrace the fact that you have a 'hill sprint' stat and a 'climbing' stat and to adopt a third 'short term recovery' stat, which would be based on how quickly riders can expel lactic acid and be ready for another effort (how quickly they regenerate their yellow and red bars) this would relate to recovering both from surges from the bunch on the flat and more importantly after hills, so that they can be ready to sprint up hills again and again and again, which is exactly what a puncheur needs to do to win those sorts of races. Pure climbers however would have a low number in this stat and despite losing less bars on the hills when they are being ridden up at a pace lower than 85, they will be unable to make consecutive efforts up the short climbs and struggle towards the end of the race once they have been drained by all the repetitive efforts. This would be my preferred idea as it would increase the realism of how hilly races work in general (actually all types of races, some riders recover from efforts much better than others), however it may require the AI to be more realistic in how they race hilly races with more surges and bunching up like in real life.
A secondary solution is what Paul mentioned earlier with setting a default mo/hill ratio for the stage like in PCM14, but then being able to specify different ratios for different sections using the spline function in the stage editor, so I could rate a consistent mountain between kilometres 87.3-104.8 to have a ratio of 1, while a short climb between kilometres 117.2-122.4 might have a ratio of 0.5 and the remainder of the stage might have a ratio of 0 (full hill) (There's a better explanation here:
http://pcmdaily.com/forum/viewthread.ph ... st_1241338), even with the method you could still keep the usage of the hill stat above 85 and for attacks so that there is some sort of differentiation between diesel climbers and punchy climbers and for the final sprint on a mountain.
Overall I am glad you guys are thinking up new ways to improve the game and listening to community feedback so thank you for that, just make sure improvements are better tested because otherwise they can be implemented with some flaws like the mountain stat being the most important stat for hilly stages like here.