I would not replace Sonya with BT. The more healers you have and fewer hitters,the weaker your defense gets as you go up in cups. I’m not sure what cups the OP is at, but once you get to a point where attackers have a good stable of heroes, multiple non-attackers become a liability, unless they have a crazy set of abilities like Ares and Albi and the like.
If you’re going to replace anyone and put BT in, replace Sabina. And then I’d pretty much put BT as tank because you don’t want Marj and BT next to each other as reds and BT in the corner is weak. So something like Caed Li BT Sonya Marjana, though that might not be stronger than what you have. Test it out. I’ll assume you’re higher in cups past the point where Boril is useful.
Justice is a good tank - not in the Ares, Hel, Guen, Albi top tier, but in the next “excellent” tier. If you have her max, then something like Caed BT Justice Marjana Sonya.