I sorta agree with Det0326, but for a slightly different reason. The large wire going to the starter is always hot with your diagram, and unless very well protected against chafing and pinching, just adds another line that can short out catastrophically. Your design, of course, will work, and removes the starter solenoid as a potential failure point. I'd rather have a failed starter solenoid than a dead short from battery to chassis somewhere along the way from starter solenoid to starter (think bad motor mounts and rotating engine assembly). Both failures are unlikely and/or rare, but the risk of a short can cause much more damage.
I spent my last 12 years doing failure analysis, system safety, and risk assessment for Navy helicopter systems, where reliability and safety are always top priorities.