While seat width indications are somewhat helpful, they only reflect the designed width of the seat itself. In the end,
The actual shoulder and hip width of the passengers, multiplied by the number of passengers per row is more important (in economy).
If you are on the wider side, get premium economy or business. If you are normal sized and traveling on a tight budget, try to get into row 17 a/c h/k (it's difficult even for Aeroflot bonus gold members).
Finally, i much prefer decent legroom over shoulder space. Aeroflot offers a good and affordable economy product. However, I'm grateful for every opup i get.