For comparison. Rebel escape from Hoth is way more unreasonable than rebels destroying the shield generator on Endor. The imperials had a massive fleet blocking the planet.
I wouldn’t call 3 Stardestroyers and the Executor a massive fleet.
It was meant to be six star destroyers originally but it got downsized for (budget) reasons?
- SPACE - IMPERIAL FLEET
Six huge star destroyers rest in the Hoth System.
And the Executor completely disappears once the battle starts But it’s probably still there. Or the executor was added after the point they had done most of the Hoth Space scenes.
to quote another scene…
- Space Imperial Fleet
Darth Vaders Star Destroyer larger and stranger than the 5 imperial star destroyers that surround it…
So it was six including the Executor