As long as they don't make him like Rajveer, it's fine
These guys don't do justice to cameos. It's like they are just brought without reason and go without a reason. Yes Arshad sounds a balanced fella , he is suave , smart, isn't a loud mouth . Being a doctor he observes people well. It's very evident that by now he is fully aware that Zoya and Aditya share a bond which goes beyond friendship. He did admit that that Aditya brought life to her smile..
He knows how to play his cards well, it's obvious that Waseem hasn't informed him about Zoyas past or the fine details weren't told and he has on purpose withheld vital information because it involves the hoodas. Anyone will guess why Zoya and Aditya are together in the first place.
He is strange because he doesn't know much about Zoya , apart from the fact that she had a past and is from a affluent family. He looks broad minded and open to second chances also. One might see a different Arshad if he comes to know everything about Adiya but in Bepannaah cameos aren't supposed to know anything, they don't even find out or ask also which might add value to their character.