Things like you are describing here are a reality of the RTW world, however it is not this simple. Sometimes you will have pull lines on a jacket, but guess what? It is not tight! 2+2=4, but so does 3+1, alas! Sometimes you can have a smooth jacket that is tight 4+0=4! Alas!. There is more to fit than just "bigger" or "smaller". It has to do with the fact that we all have lumps, bumps and curves in different places that will still be prominent in a bigger, or smaller garment if of the same cut. If you are sticking to RTW you have to try on many brands and models until you find something that is cut the best for your figure. Things should "feel" comfortable and be smooth without the sacrifice of a sloven look.
There is no perfect fit when dealing with RTW. Especially if someone has an athletic and or muscular build. If you can get am RTW coat to fit 95% correct, you're doing fine, imo.