Reason to shorten a bowlers run up.

I coach our Cricket clubs under 15's. Our first league match finished with us batting for around half an hour in the dark, we lost. We then sat down at the next training session to try to work out ways to get through our overs quicker, without losing our bowling potency. We were already running into our positions at the end of the over to try to prompt the batsmen to get ready earlier. So, we then decided that we should try to decrease the length, of some our quicker bowlers run ups. How to do this? I have asked many coaches from Level 4 and below how would they approach this problem. Most understood the reason to try to change the length of run ups but, also stressed that it was not in the bowlers interests to do so. Having said that, they did offer one solution. Blind bowling. In pairs, get one player to mark the starting point of the run up and the delivery stride, with cones. The bowler runs with the ball, whilst his eyes are fully closed. When he feels it is time he enters his delivery stride. Now he counts the paces between the two cones, placed by his partner. It was notable that all bar one bowler cut around 25% off of their run up. They also didn't lose any pace or accuracy. This drill can be used for under 11's up to adults. When is the right time, to enter the delivery stride in this drill. The right time is when you have reached a balanced, rhythmical stride pattern. As a bowler, you will know when this is, it is all about feel. The one exception, was the player that counted 16 strides, as he ran blind, he really didn't embrace what we were trying to achieve. One word of warning though. Ensure the area is big and free of obstructions, as the bowler will be running with his eyes closed. Also do not get the bowler to release the ball when in the delivery stride, as he will not know where he is aiming. If you have any thoughts on this or if you have another suggestion, to shorten the run ups of bowlers, with unnecessary long run ups let me know.