Maybe I'm confused, but is this a "give the Rebels more troops to make harder on the imps" type of scenario?
I think that at the end of the day, Empire wins; because if they can take down the shield generator and have guns pointed at the hangars, they'll just have too much firepower (hello orbital bombardments) against the Rebels. Everyone knew that the Rebels weren't making a stand at Hoth, they were simply giving officers and high-priority people time to escape.
End of the day, Empire wins this 10 out of 10.
Veers just has Blizzard Force, so no orbital bombardments for him and they only retreated due to not being able to put up a front against the Imp forces while here they have a chance, the biggest threat here for the Rebels are the AT-ATs so they just need to take those down fast.
Also the neck is part of an AT-ATs weakspot Command, so the Specforce can take down an AT-AT ground wise too. The MPTLs can also do damage, aswell as the T4-B tanks.
Edit: Also gave Echo Base(for the inside only) 600 Rebel Troops, at its height it had 7,500 combat and command personal but that would be unfair for the Snowtroopers, plus the remaining Wilderness Fighters could fall back and strengthen the base defense.