Tank or no tank

Poggle speed up is not enough to even get IG88 a first turn. Poe plus poggle TM is usually enough to do that. If 88 doesn't get a first attack, you can't ability block anyone and/or reduce protection. This is the only chance you have against certain teams; that plus the crits and the insta-followup attack to break down the enemy, so that the next batter, 86, can ohko someone. So in order to get 88 a turn, the best chance is to have poggle and poe, both.

With RG as the tank, eventually this will be a decent team. But it also has some weaknesses. Namely, your droids can't heal, except for 88 (and 88's health pool is so low it's very hit or miss if he can use it). So when RG taunts, there is no way to heal the affected toon back to over 50%. Thus droids don't take full advantage of RG's skillset.

ST han, haha, no. Again, 88 is dead for sure. Period. Droid Assault does not speed up Han, so no dice, there. The only reason Droid/Poe/Poggle works (when it even does) is by giving the other team only one or two attacks to take out or block your team, before all your droids go and hopefully take out at least one opponent and/or block key opponents, so that enough of your droids will still be alive for round two. Well, offensively, against certain teams, this might be good. But if you leave this team up, you will drop like a rock.

You need RG or Poe, at least. Han might work with two tanks, but I doubt it. Because you are losing too much DPS without the poggle buff.