Suarez was absolutely critical for them in their triumph. Not only did he score 21 league goals but many of them match-changing and game winning ones. He would have been a resounding success here without doubt.
I don't get Barca's transfer strategy. They let Suarez go because he was too old but they're signing Aguero who will be as old as Suarez was when he left and far more injury prone. Also, even as good as he is when in form, his top level also isn't as high as Suarez's top level.