The speed at which you learn an art is relative to many factors. Depends on your effort and your point of view. The real world is where all scenarios are possible.
Would you take a knife to a gun fight?
I would if I knew I would be standing behind him with the knife at his throat.
One on one I would give jujitsu an edge if winning is the only wanted outcome. They stand right in front of their oponent . They do their business delibertly and decisively. They kick and choke. Are you comfortable that no one will jump in?
If there are multiple attackers and survival is the #1 I would rely on my Aikido. The majority of the time Aikido people will stay at a dead angle to the opponent. Off line!
Is it a question of what works more affectively?
Can you feel good about your actions afterword?