One more tip:

Back in vanilla, it was common for groups to work like this:

Clear a zone. That's your base. You park dps and ranged there, and the tank moves into the next zone and pulls some new freinds into your base. You'll need to learn how to kite the mobs, but it's not hard. Burn down, rinse, repeat, move base up. Not as crucial in places like Deadmines, but it was mandatory later on when you got to places like Scholo and LBRS.

Essentially, you need to control the fight, when it happens, where it happens. Never fight them where they stand before the fight. You need to learn the Art of the Pull, kiting, and postioning. That way, wanderers have less chance to engage, and if you get feared (later on), you won't aggro half the dungeon.

Establishing bases in Deadmines is easy, it's one long tube.

For example, when you get to the Buzzsaw boss, you need to clear the goblins out of the room first (the mast room? It's been a while). Group your guys outside the door, deal with the patrol, and pull the first goblin or two out the door. Keep going until half the room is clear, then move the group in, rinse, repeat, take out the boss.