Another show I know nothing about, so bear with me. I find the best solution is to find authors I know are good from their other stories and try their crossovers. All of the below stories very much belong in the I don’t understand, but I like them category, so I present them here (still in bafflement).
The Doctor intervenes in the Earth/Minbari war.
Again, I don’t know Babylon 5, but this certainly works hauntingly well from a Doctor Who point of view.
Like I said, I don’t know much about B5, but I do know that what JJPOR writes is usually well worth reading, so…
It certainly does seem that Seven is the natural choice for a B5 crossover.