Agreed with what you are saying there star but I think the example doesn’t work because of the horizontal component, if an object travels directly upwards it will reach the highest point where it will have a velocity of 0 before travelling downwards at – 9.81 m.s. I dont think that is the case in sprint running.
In sprinting the equal flight time might be true, meaning that quicker athletes travel more horizontally during the same kind of flight time. Which is what you mentioned. Perhaps it refers to the resultant force and increased vertical force increases the horizontal displacement also
May not have articulated myself very well here…