Going back in time to the ancient Greek Olympics, there was boxing and wrestling, and then there was Pankration, started in 646 BC.
There were only two rules regarding combat: contestants were allowed all except to gouge eyes or to bite.
Breaking toes and/or fingers was a valid way to escape a lock or choke, for instance.
Going all the way back 2500 years ago, people then understood as people today understand, going to the ground or standing is up to each athlete’s strengths versus the opponent’s weaknesses. If one doesn’t train in something, one can expect the opponent will try to make you use it.
I’ve done Tae Kwon Do and Judo. The only other martial art I’ve spent any significant amount of time on is Eskrima, but I haven’t spent nearly as much as the other two. I’ve taken lessons, formal or informal, in lots of various martial arts. I did Aikido for two months, but it was boring.
Any kind of submissions wreslting/grappling along with some practical striking will make someone a practical fighter in MMA style rules as we know it. It’s all about the training method. If you aren’t training by fighting then you aren’t training to fight!
Someone asked about Aikido:
Are your goals to just have fun? There’s no problem with that you are allowed to do anything you want.
But Aikido is widely considered not practical because they don’t train through fighting like its contemporary Judo does. In every class I ever took for Judo, after initial warm ups, we did free grappling, 3 minutes per partner for 20 minutes or so, where we try to submit each other (or under Judo rules, pin for 30 seconds). In Aikido, after initial warmup, we practiced some techniques on a partner who would let you practice on him/her. That’s the major difference. In Aikido you almost never deal with someone who wants to stop you, in Judo, my opponent is always trying to stop me and in fact is trying to defeat me.
On top of that, in Aikido we never did grappling. Grappling is basically the most effective method for training your physical and mental bodies, to push your limits to new boundaries. It’s the thing I miss most about going to class and competing every day. I can work out and stretch every morning and after work, but it’s just not the same as fighting an opponent.