If this has been stated elsewhere apologize for the redundancy, but I didn't see anything in the GW guides recently posted or any similar tips in the numerous GW complaint threads.
The idea here is to use the TM rollover from node to node to your advantage. The TM rollover hurts you when facing a tough node and trying to use a weak squad to burn enemy specials because when you go back in the enemy has their TMs already up and you're under heavy fire instantly. At first I thought the TM rollover change was bad because it really eliminates this tactic we'd used for some time. However, if you use the first 3-4 easier nodes to rotate in multiple teams and toons of your own it gives you a stable of 12-15 TM boosted heroes to use in later nodes.
I'll give a specific example. My node 1 team is rebel based with Rey/GS:
AA, Rey, Leia, HRS, and GS - here I'm just trying to kill stuff fast and not lose protection
Node 2 I'll then bench those 5 and bring in droids:
HK lead, 88, 86, JE, and B2 (could be Magna, B2 isn't critical here) - again, just trying to kill stuff fast. The nice thing here is that JE pushes up droids and 47 keeps them there - so you don't need to keep JE in your droid setup anymore - you can put in a high damage character to kill stuff before you lose much protection in later nodes - like Rey or GS.
Node 3 / 4 I'll bring in select other superstars to rotate in to these already TM boosted teams that I used in nodes 1 / 2.
For example, since I know I'll use them in teams probably later on, I'll drop JE and bring in Phasma so that in a later node her TM is juiced and she will go before the enemy. I'll drop B2 and then bring in Yoda or maybe RG. I'll do the same with QGJ and stick him in the Rebel squad, dropping HRS or GS generally. I do my best to let the TM boosted heroes actually kill stuff and at least on the recently added heroes, because I'm wanting to save their specials for later nodes, I don't use their specials. They are just in there to get the TM boost for later on. So on node 3 when I bring in Phasma I won't use her VM or speed down. I'll do the same and rotate Dooku in also, as he's a key leader skill and great vs. later-node Jinn leads.
This then lets me create some cool droid / high damage mixed squads as well to funnel in / out. Through some nodes I'll use HK leader, 88/86 with GS / Leia / Rey depending on what the opponent is. Leia will generally be in there if a 5s is present so that she can safely attack him while stealthed and bypass his protection-killing counter barrage.
The other advantage this has is I can sub in / out TM boosted toons and go around key cooldowns by subbing in a TM boosted toon that isn't on cooldown so that I always maintain a high % of my team with critical specials ready to go.
The TL;DR .... funnel in as many of your better heroes in the first 3-4 easier nodes of GW so that you have a group of about 12-15 turn meter boosted heroes that you can unleash on later nodes that are more difficult. This allows you to always go first, have a deep pool of specials / skills to attack with, preserves protection on your best heroes, and it speeds up the GW as many nodes you are killing the enemy before they have a chance to move.