As we approach the summer months, the continued "early" struggles start to become season-long issues for many players. Those slow starts in April and May can be brushed off or shrugged at, but they become harder to overlook now that about 40% of the season is in the books. This marks a good time in the year to take a temperature check for your fantasy rosters in dynasty leagues.Whether you're buying or selling over the next few months, it's important to maximize the value of your assets. Here, we'll take a look at some…