Preferred CB pairing Andersen vs Tomkins

Help me settle a debate. I was having a conversation with a non BBS-er about how we've stumbled away from our successful system from earlier in the season. I argued that Andersen's absence from the last two games has seen our ability to build attacks and maintain possession has worsened. He argued that this was offset because Tomkins is a better defender and that we could still play in the same way with Tomkins in the side. He also went on to suggest that if Andersen is such a good passer that he should play DM. I disagreed strongly with this and asked "why are you trying to change so much that was good from our opening games?" before arguing that the base Andersen and Guehi have provided has transformed us into playing a possession based style.

Sometimes one can stumble into an echo chamber and not realise others have a different point of view, but I suspected the vast majority would prefer Andersen and Guehi.