True. There would be a tradeoff. A person playing an O5e Eldritch Knight would be getting their spellcasting ability instead of a proficiency in a third combat tradition at level 3. And they wouldn't be any worse off since they still would have the proficiencies for the two combat traditions at level 1. They would be just like the Herald, the Marshall, the Ranger and the other fighting classes who just have two combat traditions under their belt. Still...I can't help but wonder what an A5e version of the Eldritch Knight would look like.