OP, while on the surface there doesn't seem to be a rhyme or reason on the assigned SL, this is likely due to DC being your first card with Citi and already having quite a bit of available credit relative to income. Had this been your 2nd or 3rd CC with them then the results would've been more favorable.
Can this be overcome? Sure. Over a period of time. Now, keep in mind that you can try the EO route as mentioned above but they do not make the CLI decision and you don't get to speak with their UW unit. They simply forward your request (or grievances) for reconsideration and this would result in a HP. As with anything, maybe worth a shot, but YEMV.
So, if the CL seems to be somewhat of a minor set back or inconvenience, you can try that approach.