I have several issues with this...
1) Pulldowns and rows do not hit the same muscles as a high pull
2) These two movements do not involve the whole body like high pulls (I want an explosive whole body movement)
3) Who says that technical complexity is a bad thing. Sure a full squat snatch might be too long to learn to be effective for most, but high pulls, even though they are somewhat technical (well in truth they are more about coordination and timing than pure technique) can be learned by everybody and at one point, learning a skill is beneficial
4) I tried high pulls with a pulley and it doesn't work... there isn't enough weight on the stack (at least for me) and if you have enough acceleration (which is what you want) the stacks "flies up" and then drop which is hard one the cable and pulley