Siege of Phandalin help
Hey!
So I'm running a LMoP campaign, as my second time DM'ing ever. It's HEAVILY homebrewed and I've added a lot more meat to it, improvising to adapt the story after seeing what my players enjoy doing the most. They did things in very different order (Ambush - Phandalin - Old owl well - conyberry - cragmaw castle - redbrands - thundertree), and are now returning from Thundertree to put all the puzzlepieces together for the final push into Wave Echo Cave.
My plan is basically to have a goblin warband raid Phandalin while they're preparing to go to WEC, we're talking massive fight involving the party and the npcs in town. It's the last push from the remaining goblins, being sent by (a now VERY deceased) Glasstaff, armed with a kinda supermutant serum making them mutate into shortlived but strong mutants.
The last part of the raid will be a bossfight against a very resident evil inspired massive orc mutant, sent as a last resort.
MY QUESTION: How do I balance a massive fight with like, 30-40 goblins total, 10 ish phandalin militia and sildar, gundren etc, and without it taking a hundred years to finish? I've never done a large scale battle like that.
I want it to feel epic, they've been harassed by goblins this whole campaign. We're talking doomslayer style mowing down goblins left and right. The main fight is the acutal orc mutant.
Any feedback is appreciated, it's a big moment in the campaign.