Your team is like g9, and as you mentioned, you don't have RT starred. And no zetas on the team.
a HSTR will be closer to g12, full zetas. I'm assuming you don't have 40-100 zeta mats, corresponding omegas, and all that gear except the multi-tools
that said, I ran the team against t6, (also not maxed out, but with 5 zetas and g10-11, 9 on JTR) and they managed to stay alive without a healer. Healing zetas (on JTR and BB8) and foresight were key, but they stayed alive without the multi-tool. (Scav Rey apperntly does enough damage to heal naturally, and I think RT was the same but not sure)
by (heal naturally) I mean she has enough life steal without the g12 peice