My wife got a job in the UK and I was covered for work as a spouse. We work for the same company. I would guess a basketball team won't get a work visa for his fiance but could be part of the deal.
Yes, but I think we go into hypotheticals beyond norm. It is a lot different for a company offering two employees, or husband/wife, employment, legal help, etc. especially if they really want/need one of the two. But unless you it is an NBA team, or in this case, a high level Euroleague team, they will not absorb such large overhead offering his fiance a job, hiring immigration attorneys, or cutting deals with investment banking firms. If they were willing to do so, they would just offer higher salaries to begin with.
Black is nowhere near Euroleague level. International basketball can be lucrative at the high end, but for many players it is not a great financial proposition, actually often a financial sacrifice for keeping their career and dream alive.
Best of luck to Leron in whatever he chooses!