No, SMT techniques only help with throughput, not single threaded execution latency. Furthermore, if you have no OoO, then it's very likely that both threads will suffer a cache miss. Plus the overhead of SMT is very similar to just having two cores. Modern CPUs reuse much of their OoO circuitry for SMT, removing OoO means that SMT has greater relative overhead. (I can dig up the relevant papers if anyone's interested)