This build let me solo dread dungeon. I don't know the minimum stat requirements for builders, but all of mine are around 1K-2K (except my summoner which has 2.5K minion health and 3K minion damage), so it should be relatively easy to achieve with fish and/or mythical armour.

Hint 1 - For the first wave, build a wall of 4 archer minions with a mage here to block this side off, then use a DPS hero to kill everything that comes from anywhere else. This is your most stressful wave. After the wave is done, sell the archers and mage and replace them with the Forest Golem.

Hint 2 - There are 3 archer minions stacked here. Make sure that they are just inside of the Forest Golem's healing/resistance aura. Additionally, if you didnt get enough mana during the fight of the first wave, place these last.

Hint 3 - There are 4 DSTs stacked here -- 2 facing north, 2 facing south

Hint 4 - This archer wall is extremely important. Build it as soon as you can after the first wave is dealt with by your DPS.

I upgraded the Buff Beam & its towers first, then the golems then archers then mages. Everything was fully leveled by wave 15. It's nearly AFK-able, the towers just need a minor amount of help starting around wave 20