No it's this game that did it wrong, not Lucas, there's a lot of potential for Imperial characters that they're just not using. The obvious missing Imperials are Krennic and Deathtrooper, but they could also bring in Thrawn since Rebels made him canon again.
We got seven Rebels from Rogue One, which is two too many for a full team. Why bother with Bistan and Pathfinder if they can't even fit in the full Rogue One team? Last year we got five First Order and five Resistance which allowed for a full team for both factions. This year we got seven Rebels to one Imperial.