Striking is really fun. A friend of mine taught me some basic boxing techniques but you’re right I’m taking on unnecessary risk. I’m not a small guy but there are definitely bigger guys that have better reach and more power. My friend is 6’4 and over 250 pounds. I don’t really have a chance going blow for blow against him but a good grapple of his elbow is more doable.
Discussion
Big boys have an advantage grappling too. Rough estimate is 20lbs is a stripe worth of skill. Of course not every 20lbs is the same.
If you know how to fight and they don't though, that is a different matter.
The skill of blocking collar ties and lapel grips transfers to blocking strikes. Strikers don't learn any skills that translate into a takedown defense.
So much fun to repeatedly block then takedown when I get to play with the people I know who are TKD blackbekts.
Also, 2 ish years for TKD or karate blackbelts instead of 10 for BJJ. Easier to add striking at any later date to round it out.
I never heard of 20 lbs to be equivalent as per stripe, I'd strongly argue against this. Size matters but not to that degree some people despite their size are still tremendously vulunerble under the guise of BJJ.
No magic and not hard and fast. Just a rough estimate of how much skill weight can cover up between 2 trained opponents. So far it is a decent guess based on my mat time.
Stretch it out a bit and see. How much training to consistently beat an opponent with 100lb weight advantage but no fighting experience? About a blue belt. I'm a bigger buy and 80lbs is definitely enough to get tough rounds with smaller guys a full belt ahead. Guys my size a belt ahead I need a bit of luck and to have my A game fit perfectly into their biggest weakness.
Every person is different cardio matters and not every pound is muscle. I know a white belt former wrestler who requires my A game to survive even though I've got 60lbs on him.
Two opponent sounds like one would need to just run away! but I rolled with this guy just a few days ago and he has a few weeks xp and probably 80 lbs more than me and he is very much vulunerble. I have another guy slightly less rank, which means nothing in terms of stripe but a 150 lbs advantage and it depends on the position whether he can dominate eme or not. If I'm on top of we are on our feet I have an advantage but if he is on top of me then it's like getting mauled by a bear.
At that point you need to use street fight tactics. Eye gouging, scratching, biting whatever 😂
In judo if you land a throw where your opponent lands flat on their back it is an instant win. The reasoning is someone who doesn't know how to fall on concrete is dead or unconscious if that happens to them, without mats even a trained person may be fucked. A good takedown can be over in a second.
For multiple serious opponents I think hard throws is probably your best bet.
Or...

ya if they're trained they can do that too but even better by holding those positions better and takinf their time to do all of the above.
Do it all, striking and grappling.
Every fight starts on the feet and usually ends on the ground. That’s why joining an MMA gym is your best bet. You’ll get exposure to every aspect of fighting.
A lot of pure BJJ gyms have people start on the ground, so they miss out on key skills like closing the distance, executing or defending takedowns, and dealing with strikes. They also don’t learn how to roll with punches, which is obviously crucial in a real fight.
As for striking, just make sure you’re training at a solid gym where people know how to spar properly.