Personally, I prefer stand up grappling arts (like Hapkido and Akido) over ground arts (like BJJ) simply because it is my opinion that being on the ground in a self defense situation is Bad Idea (tm).
Judo is a good place to work from if, especially if you like the idea of competing (even within the dojo). You'll get a more limited range of responses in Judo than in something like Hapkido, because they tend to distill down to what works against other Judoka (and further, often, to what is allowed in competition), which is a much smaller population of techniques than what will work on everyone else
Both wrestling and BJJ have a focus on moving to the ground. The best use of this is that you'd also be training on how to avoid going to the ground. That latter, you'd also get a good focus on from Judo, with the added benefit of much more focus on being able to put the other guy down without necessarily going to the ground, yourself (though there's a reasonable amount of that in Judo, too). With other standing grappling (Aikido, Hapkido, etc.), it depends on the school how much you learn to avoid being taken to the ground. If there's resisted training (two people trying to put each other on the ground), you'll get that benefit. If not, probably not.
Then I'd say jiu jitsu. Wrestlers don't spend a lot of training off their back, judo from what I know spends more time in a standing clinch and works on throwing your oppenont and it has some emphasis on mat work but it's not the focus. But jiu jitsu spends a lot of time on your back teaching either submissions from your back or sweeps and reversals.
Juijutsu akido Krav Maga and Kenpo
I think for this reason, BJJ is an excellent compliment to your TKD training.
Otherwise split the difference and do submission wrestling.
Where BJJ + TKD will get you more threes, I think Judo or Wrestling will get you more 2+ scores on your chart.
hapkido traditionally goes well with TKD, judo will help you grappling while staying standing, BJJ will help you if you end up on the ground. It's up to you what you value more.
I would say BJJ. It helps you with the area you're the least proficient in.
For that combination, I'd be thinking either Judo (because there's a really good focus on not being taken down, plus some reasonable groundwork) or BJJ (because that builds strong competency on the ground, and many places do teach getting up after you get control back)
For what you want, Judo is more likely to enhance your ability to stay standing (and handle a clinch). BJJ is more likely to help you handle things on the ground. Decide whether you're more interested in dominating on the ground (advantage to BJJ) or being harder to take down (advantage to Judo).