The only 'incident' I've ever heard of for the 'Throttle pre-positioned to just below idle before hitting start switch' method was when a very new-to-turbine engines pilot was partway through the start and had a loud buzzing noise in his headset. He immediately shut off the start switch without shutting off the throttle.
My friend sitting in the copilot seat watched the TOT go through the roof, and later picked up bits of melted engine off the tarmac. Needless to say, pilot was not long with the company.