Where in the world are you compiling this information on arm angle, run ride, etc. ? You mentioned that Chris Sale, Josh Hadar and Jacob Misiorowski have more fluidity that allows them to generate more velocity on their pitches. While fluidity may be a factor I don't think we should discount their physical size [ height and arm length when extended ] . Their pitches do not travel as far because they are released closer to home plate than normal pitchers. And they arrive at home plate even quicker.
But back to Palencia. I thought that he worked too hard before the season getting his arm [ and body ] into shape for the World Baseball Classic. He was outstanding during March as the closer that saved the title for his home country. I anticipated a drop off in his performance at the start of the regular season [ cold weather doesn't help ] and he eventually ended up on the DL not once but twice. The length of his last DL stint as well as his performance when activated makes me believe he is still not 100% and still dealing with discomfort in either his shoulder or elbow. I believe that he is still trying to fight through the discomfort and work himself into shape to be effective. He is a warrior and will give it a go until the results tell him it's time to shut down for the year. I agree with you that although I hope he can regain effectiveness, I anticipate that he won't get back to his 100% self until next year. One thing that I noticed is that when he is nursing his body when he comes into pitch [ due to soreness, pain, stiffness, etc. ] , he is sweating profusely. Something to watch for in his next few appearances.
Question though : Do you think the change in arm angle is due to pain, soreness, or stiffness ? Are the Cub hurlers versed in their arm angles and the movement on their pitches ?