I don't think this would be a practical "solution" in context of this thread's topic.
But beyond that I do very much like your general idea of supply ships steaming to the fleet in regular intervals. Apart from being helpful in reconnaissance for the enemy fleet, they could make great additional targets and add another variety to the gameplay.
It would also be quite realistic.
My grandfather was on a tanker in the South Pacific. USS Monongahela (AO-42) 10 battle stars
He has told me on more than one occasion that he felt safer when caught up in battle when with the entire fleet than when they were alone, steaming to resupply the fleet or when sent away deliberately, due to an upcoming battle. When they were served steak & eggs for breakfast, they knew the doo-doo was going to hit the fan.
He said that the worst was when they were alone, with only a small escort (and their own guns) to protect them.
With a max speed of 16.5 knots, carrying max load of 133,000 barrels of a variety of different fuels, it took them almost 5 miles to do a complete about-face to head the opposite direction, so maneuvering during battle was all but useless.
When not with the main fleet and in a small group, they were nearly invisible to spot but if spotted, it made for a long day..
