Yeah, I see what you mean. But I see Ichigo and Orihime more together. And while I'm sure that Nel did have some feelings, it was a pretty short interaction.
Now, if it were in the actual manga/anime, I think it would be more Grimm/Nel, because Kubo has already got Orihime to confess to Ichigo, and it's kinda obvious that she really loves him. Then their's Renji Rukia..... But yeah, I see your point. It's just that if it were in the manga, I think he would choose Grimm/Nel if there was supposed to be an arrancar couple.