The GT 750m seems pretty weak compared to the GTX460 (the minimum gpu required for over watch) using passmark and futuremark benchmarks as reference. Sorry :(
Overwatch System Requirements:http://www.systemrequirementslab.com/cyri/requirements/overwatch/12955
GTX 460
Passmark: http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+460
Futuremark: http://www.futuremark.com/hardware/gpu/NVIDIA+GeForce+GTX+460/review
GT 750m
Passmark: http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GT+750M
Futuremark: http://www.futuremark.com/hardware/gpu/NVIDIA+GeForce+GT+750M/review