Warriors can't backstab, can't pick locks, can't disarm traps, etc. etc. etc.
As I said, you don't need any, or at least a very minimum amount of, hard points in str to equip tier 3 WCA (you don't want higher, unless you are prepared to invest in the str required). --- R.I.P. Eve English (Feb. 12, 1968 - Oct. 13, 2010) Momma Eve, you will be missed.
You do not need a single point invested in str, period, you do not need to dupe tomes, you do not need anything other than the points you get from the Fade and str+ gear to temporarily boost your str to 26 to equip tier 3 WCA.
If you make choices that keep you from getting certain str+ items, you may need to invest a few actual points, but nothing major, and most of the str+ gear has alternatives, especially now that all the promotional DLC is available to everybody that can connect their console to the internet. --- R.I.P. Eve English (Feb. 12, 1968 - Oct. 13, 2010) Momma Eve, you will be missed.