Swgoh farming flowchart

Much like Light Side and Dark Side battles, Fleet battle hard nodes are limited to 5 attacks per day before needing crystals to refresh further attempts. Including the one Fleet Energy payout per day, you'll generate 285 Fleet Energy each day. As such, I recommend 10 Fleet hard node attacks per day, and using any leftover energy toward hitting fleet nodes for specific gear pieces.

Also like LS/DS nodes, a large number of early importance characters are found in later nodes that may be too difficult initially. Your focus should absolutely be on reaching those nodes as soon as possible, while growing your ship strength through the various stores and earlier fleet nodes to reach those later stages and clear them (chapter 5 in particular is incredibly difficult).