So you are 173cm, and looking at a 180cm dollos.
First off thats a 7cm difference, which is not that huge, being that they are Armada skis, they will end up measuring 2cm short, so that means they will be 178, thus 5cm above your head. So now we have a ski that is either 180 or 178 depending on how you measure it. There is another way to look at this, ski size relative to height. 173/180 = .96 and 173/178 = .972. Thus you are within a height range of [96%, 97.2%] of the skis length. (ie: you are 96% the height of a 180cm Edollo ski)
How about we do this analysis on Harlaut, after all the ski was designed for him. Based on this photo of him, we see that he is riding a 180 Edollo (look just below the toe piece of his binding). Harlaut is 5'7" or 170cm (https://en.wikipedia.org/wiki/Henrik_Harlaut). Now if we do the same analysis as before we see that Harlaut is within a range of [94.4%, 95.5%] of his skis height which means he is smaller than his skis by a greater margin relative to you to you.
There for, you are not sizing up, and are getting a ski that is a relatively good size for you. Go with the 180, I think it fits you better than the 174.