With his huge amount of infection, he could work very well behind a tanky defence lead such as Pete or equally well behind a lead that will slow down the opponents attack by shutting them down for a turn such as Mercer or Jacki. I think the Tanky way will work better as Trader will force the opponent to bring heal toons which could reduce their offensive capabilities at taking down a tanky team.
Off the top of my head for defence: Pete-Trader-Princess-Frost-Shiva with big focus on hp and ‘def against’ not ‘att against’ mods.
Pete: Hp bonus kept on weapon rather than stun and maybe 10% def to all teammates for each red (20%). Impair resist and stun resist as well as tanky mods, maybe a Graze or ap down mod.
Trader: Tanked up weapon crafts. 4th slot could be 35% heal reduction as this will stop Aarav’s weapon curing infection which a lot of top players will be using to stop his infection. Disarm/Stun and Daze resists. Graze.
Princess: Swap out her weapon for Elusive Impair for this team (keep her normal weapon rather than crafting over it though as it’s great for attack teams), 4th slot 5% bonus hp to 2 teammates for each blue on the team (15%). Taunt and Daze resists. She’s in this team for her AS not AR hence no focus on boosting att for that great damage AR. Reflect damage mod.
Frost: Elusive Impair weapon with 10% healing for 2 turns for each debuff. Taunt and stun resists, reflect mod.
Shiva: In line with Frost. Attack increase on her weapon changed to defence, 3rd slot kept, 10% healing for 2 turns for each debuff or reduce damage from basic attacks by 15%. Graze mod, disarm and stun resists. Not here to primarily be a payback but to be an exceptionally tanky toon who taunts opponents onto her bleed claws and can take most heavy ARs in her stride without even activating her Payback, but if an AR does hurt her then she will activate and do significant damage. Helps protect Frost from Aarav who will be a toon whose AR activates her Payback.
With a team this Tanky, it should give Trader ample opportunity to be hurting opponents with infection.
Opposing attacking Traders and the new Storm toon will hurt this defence though.
Edit: Any of the Graze or relects could be replaced with ap down for equal efficiency.