Still-human Fifeld or full on alien assimilated Fifeld?

The more I look at the dismissed concepts for what Fifeld was transforming into and, instead, was swapped for the human contortion Fifeld, I think this was a very bad judgement for Ridley Scott to do. I think I understand that he wanted to distant his ideas from what has gone on in the first movie, but I think this was an error. Anyone else agree or disagree?