Every room is different. I too have my Strads about 3’ from the back wall. The low end is too wooly and I have chosen to use Subs to play the lowest octaves and plugged the Strads. Far better low end.Just to add another view on this, my Strads are placed 3 feet out from back wall and 2 feet from side walls in a 13x24 ft room without any specific room treatments and bass is just tight and fine. Though I have all my equipment on Ansuz Acoustics Darkz DTC which is a big reason for the in room results. But, consider amplifiers that can give good support in the 2,5-3 ohm area.
Mike
If I could pull them out further, I believe they might be fine on their own. That is why I suggested with flexibility in placement, they would work in the OP’s room. Without flexibility, I would have said to be prepared to use subs and leverage their placement flexibility.
The rear port of the Strads needs to be placed perfectly in a given room to offer the optimal low end.