I am trying to follow you here, and from what I am understanding you are questioning whether it is a correct fit. I would like to ask the following, did they measure you? That is the old fashioned way to determine size. As we age our shape changes. Most of us have a rough idea what our size is in suit coats and slacks. As you have identified tailoring will vary from brand to brand. Perhaps this is a very trim fitted suit and you may have a athletic build w/ a broad chest and shoulders and a small waist. A salesman who knows his business should recognize this and direct you to suits that are tailored to fit your build. So start w/ what size you believe you are or they measure/estimate. Then try one size up and one size down. You see where I am going here. It should be obvious which looks and feels like the correct fit. Remember too, that jackets and pants are sold typically in even sizes. So for example, you may actually have a 43" chest. So you try on a 42" and a 44". Normally you go up a size and then take it in (tailor) My fear is the salesman pushed you into a suit one size too small and is telling you they can let it out. Sad to say, if they work on commission and they didn't have your best size (fit) they may have sold you a size too small, in order to get the sale. If it has been tailored and you are really not satisfied w/ the fit/comfort, ask to talk to the manager. Try the suit on for him, then look him straight in the eye, and ask him to confirm you were sold the correct size. If you still question it. Go to a independent tailor and ask them to measure you for a suit and slacks. If it's the same as the suit, try it on and see what his opinion is regarding fit and tailoring.