Split runs for L-TO-S Question

My athlete has had more success with the split runs than the full distance (i.e. 100-100-100; 150-150; 200-100 instead of running 300m). His performances were noticably better off the back of split runs than when trying to run the full distance. I have therefore decided instead of moving the split runs toward the full distance, to keep all SE1 and SE2 runs as splits with the volumes decreasing to allow for increased intensification. I know this works for short-to-long for SE distances, with the splits increasing, but does this work going in the opposite direction? Has anyone had any experience or success with this?

Perhaps he had more success from the split runs due to other factors within the program rather than the split runs themselves.

This is always possible, especially with younger or less fully developed athletes.