It seems like considerable losses could have been avoided if communicators were used between the rebel strike team on the ground on the surface of Endor (disabling the shield generator) and the Rebel fleet attacking the Death Star.
The idea of relying purely on timing for coordination of an attack with so many unknowns (including how, specifically, the strike team would disable the shield generator and thus how long it would take) seems incredibly risky unless absolutely necessary. It also seems that just building in sufficient margin so that the fleet engaged with the Death Star well after the shields would have been assumed to be disabled isn't tactically sound either, since this would give the Death Star time to realize its shields were down and prepare the Imperial Fleet to repel an attack.
Is there a canon (or even Legends) explanation for the lack of communication between the Endor team and the Rebel Fleet?