Well, you ask whats the importance of a 15 attk IV.
Like...it could be a relevant question if you was comparing a 11 attk to a 15 attk.
However in your case, you are comparing 14 to 15 attk ivs. The difference is one, a single attk IV.
This sort if difference is pretty much gonna not be noticeable in game at all.
So i would say go for the higher IV one overall.
The 93 one, overall has a single extra IV point. Its a total of 3 away from perfect instead of 4 like the 91% is