Every athlete interprets a “cue” differently. The main point is to determine if the athlete is accomplishing what is required of them. For Tellez’s athletes - they did not do the same type and amount of strength work that Charlie’s athletes performed. So telling an athlete to “PUSH” may be more appropriate. While Charlie doesn’t want his athletes to Over-PUSH because they are so strong and may over-commit on their extension phase. This is why Charlie constantly talked about the arms. His athletes’ legs were sufficiently strong and powerful (from lifting, med-ball throws) that they didn’t need to focus on that quality. It was present in all their start work.
As an example, female athletes tend to respond better to cues that include “PUSH” and be “POWERFUL”. Stronger male athletes that I work with tend to respond better to being quicker, lighter and thinking of lifting the knee/foot off the ground quickly.