The alternative to having PCs play commanding roles in significant battles is to have the battle be completely out of their control, and have them helplessly watch from the sidelines. Or even more remotely, the battle happens elsewhere and they only hear about the result afterwards.

While this can be unsatisfying if the battle is the direct logical outcome of their actions, you can use this sort of remote battle as a tool to make your campaign world seem alive, rather than a static sandbox in which the pCs are the most important motive forces.

Have a messenger arrive in a tavern and breathlessly announce to all that the neighbouring kingdoms have gone to war, and vast expanses of land have changed hands already. Or when the PCs arrive at a destination planet they are shocked to find that there's been a violent overthrow of the government, and the previously friendly port where they sold cargo for profit has turned into a dictatorship where their kind aren't tolerated any more.

Transcript

R2-D2: There are no PCs up there! I'll take command of the space battle.
GM: Good idea.
R2-D2: Wait... what, really?
GM: Sure. It's a significant part of the encounter.
R2-D2: But Han was sending them orders before.
Han: You can do the mundane tactical details, while I command the grand strategy.
R2-D2: All right. Sounds good.
R2-D2: What's the strategy again?
Han: Full frontal assault on the Peace Moon.
C-3PO: But it's a sphere...
Han: Right. Attack on all of the fronts! You handle the details.
R2-D2: Got it.