Apparently Kaido just wanted to use SMILE to bolster his crew's fighting power to make his army a big enough threat to copycat WB and fight a huge losing battle.
So in Luffy and Law taking down Doffy they are getting in the way of Kaido's suicide attempt.
Also I have a feeling that rather than Kaido being crazy powerful I think this chapter proves that the dude is mostly just crazy durable.
So in Luffy and Law taking down Doffy they are getting in the way of Kaido's suicide attempt.

Also I have a feeling that rather than Kaido being crazy powerful I think this chapter proves that the dude is mostly just crazy durable.