Ranks make the High higher and the lows as low as possible. If you want your Players to have a higher chance of doing cool stuff, and make failed rolls rare and impactful than ranks can work. I just think that the “use a rank to add” +1 system might be a bit too powerful. If you want to use a less powerful version, I reccomend just making it a +1 on Rank 1-3 and +2 if someone gets to Rank 4-5. The second draft will include an entire chapter on this, I have already started writing it