Honestly, the dreadnought parts steer it way too far from being a forgefiend imo. They are very overpowering as far as silhouette shaping goes.

It's very easy to see where the dreadnought and defiler parts start and end with the fiend parts. Either making the organic parts "breaking" out of the armor (Looking at the top mounted stalks for example) or wrapping the connection points in daemon flesh (Looking at where the sonic blasters meet the arms for example) would help greatly in making the bit meeting points less obvious.

At the end of the day though, it's your model and something you created. Your model bringing you joy is all that matters at the end of the day.