Hi folks, as Kyno mention, these units are also being granted a Bonus Turn. Which means the unit that will go first will have the highest amount of Turn Meter, then highest speed if tied for TM, then randomly selected if tied for speed as well. The new system for turn order specifically prioritizes all the units with bonus turns over any other units.
In this case, the enemies in Tiers 3 and 4 of the Smuggler's Run event are being granted a bonus turn as part of their event buffs. If Han Solo has no Turn Meter at the end of an encounter, it is possible for the enemies to go before him if they have more Speed than he does.