What the hell is a coc explosion attack??
How is it not apart of swordsmanship when haki is apart of swordsmanship?
Why is Luffy not using a weapon if it's supposedly not needed to have any mastery over it? It's pretty much meta if we look at toptiers, more than half of them got a weapon.
Would Roger be just as strong as garp if he dropped his sword?
How is it not apart of swordsmanship when haki is apart of swordsmanship?
Why is Luffy not using a weapon if it's supposedly not needed to have any mastery over it? It's pretty much meta if we look at toptiers, more than half of them got a weapon.
Would Roger be just as strong as garp if he dropped his sword?

As kaido stated, haki transcends all. It's basically all about haki in the end. Swordsmen only use an additional tool to channel their haki. Thus, they even have more control over their haki than those who use their 'body' to channel it.
On the other hand, non-weapon fighters that pick up weapons would need longer adaptation time to be as strong as they were before without weapon cause they'd struggle with the channeling/haki management.