Any engine with only a front mounted motor and a dummy rear truck isn't going to be a great puller. I had the same issue with the Lionel Phantom, and the fix was to add a rear motor: Improving the Lionel Phantom Locomotive
Note that it already had a Pullmor in front, but the issue with only a front motor is traction more than motor power. I added weight to the front and that had minimal impact, but adding the rear motor was like night and day.
Nothing stopping you from adding TMCC to the engine as it is.