Yudhi and Kunti bear more blame for it to be sure. But Arjun did plenty to blamed for as well.
1) he went there knowing a human being is going to be parcelled between the 5 of them. He was not a fool from any reading of the epic. Neither was he that devoted to Yudhi that he could not see the wrongness of what they were about to do2) He made a decision for Panchali without having the right to do so. Engaged or married, to suggest one's fiancee/wife consider taking on 5 men, is not something even men of that Era did on their own.There were always options for Panchali1) Insist that Arjun marry her, which he wouldn't given the God like esteem in which he held Yudhi.2) Insist she be married to only Yudhi which is where the disunity business comes in, I suppose. That's why Kunti had to say it.So rejected she could1) go back to the same Panchal which rejected Amba's request for sanctuary under similar circumstances and take the same path that Amba did and kill herself2) Go to Dwarka and live a life of obscurity
Anu point 2. If she is legally betrothed to Arjun, can she say no to him (of course Arjun is also saying the same, but still) and insist his other brother marry her?
This whole Kunti drama - at least the P's can say mom said so we have to. Can Panchali say the same - u know laws r diff for men and women. Can she say, since Arjun is refusing to marry me, why not Yudhi being the eldest marry me.
I think she should have picked B, N or S. Y and A are so 🤔