In a perfect world we could all measure our spaces and know exactly what we needed to do in order to make a space work best for recording. That's pretty much not going to happen in many situations.
A workable fall back position to that in my opinion is to use generality to your advantage. If you have a room like most rooms used for home studios,then you can safely draw certain conclusions. Bass in these freqs. will do this and that and the higher reflections are known to do that and this.Those rules don't change in certain of the
most common room types...squares and rectangles with fairly common lengths, widths, and heights. The same rule applies to most sound treatments designed to correct standing waves. Bass absorbers are sold for the purpose and cover everything within a certain range. Wall foam panels are effective to a certain level where the bass traps leave off.........if you know that bass waves tend to reside in corners and if you know the areas where mid/high waves tend to gather and reflect, you have enough info to treat your room to a level that will get you where you need to be. The entire process from start to finish based on general knowledge about spaces and how they behave...not one measurement taken.
I think both approaches are best, but if you want to record and you can't put up sound treatments, then I think ARC can help.