wheres the training for defense against knife attacks an mutliple opponents?
If you want to learn knife defense, WC is not your best option.
Most of the bare hand defenses/blocks in WC will get your limbs shredded against anyone who has the faintest idea of what to do with a knife. IMO you’d be better finding a decent FMA or CQC teacher. A good teacher will impress on you how foolish it is to fight someone with a blade if you don’t have a weapon and you have any chance to escape.
Butterfly sword techs can (THEORETICALLY, and this is of course an anti-theoretician forum!) be adapted to a knife fight, but you can’t realistically carry such weapons - you’d be better off learing to use an impact weapon like a walking stick. Or running away.
As for multiple opponents, yeah you can look at some scenarios. IMHO WC is better suited for fighting a single opponent, or multiple opponents in a corridor, so none of them can outflank you - styles like CLF have better tactics (in THEORY) for people coming from all directions. But the same applies as to knife fighting, the odds against you are considerable and you should avoid this if you possibly can. IMO, others will probably disagree.
Your roadwork and interval sprints are probably your best form of training for such eventualities.
I would imagine your boxing and kickboxing gyms didn’t have a lot to offer in this regard. They know their areas of expertise and sensibly do not venture outside them. Not so with too many TMAers (and MMAers - didn’t some MMA fighter get wasted in a street fight recently? Brought his RNC to a knife fight?).