Cross-training benefits those who are trying to optimize performance, imho
If you are seeking to compete more, you can schedule your races with a calendar. For example, once you've planned out when you'll complete the RJ training plan, take a look at other subsequent races. You'll be in shape and you might enjoy continuing to do more.
This all gets into race scheduling with events rated by importance. If you get any triathlon book, like "Training Plans for Multi-Sport Athletes" by Gale Bernardthttp://www.amazon.com/Training-Plans-Multisport-Athletes-Ultimate/dp/188473782X
you can then get a template to build out your entire racing season.