little late to this....
If you have any 5*'s, they're usually find for clearing the lower nodes for basically "free".
For the Venom event (not simulator), I got a LOT of mileage out of Rocket & Groot. Just keep an eye on enemy levels, and walk him out to the front to eat the damage, match yellow to heal to full.. rinse and repeat. Cycle DPS characters behind him (2* Mags makes a good teamup for blue generation to get his massive attack tiles out).
Patch/OBW/IM40 has been my go-to team for goon nodes (and nodes with 1-2 goons + regular). Make 2 yellow matches, fire off yellow, patch green & red, obw blue to delay goon nodes then let OBW clean up with her double-dip strike tile damage. This obviously won't work if you're in 4* land. Patch tanks everything, goons shouldn't get a shot off. If it's a bad board, simply retreat before taking damage from anything. You'll lose much less health this way.
The required nodes have been horrendous for me. 2* Thor doesn't have the punch anymore, my 3* beast is poorly covered, and my Kate is even worse. Again, Rocket & Groot has been my savior.