Long reining isnt used to just teach them hacks its a very good training method to help a horse that dosent have the confidence to stride out on his own merit, infact I longreined my very nappy driving horse for a full winter without being ridden/driven etc or with company to resolve his issue. Napping is dangerous if they are doing it on the roads. Its horses for courses really, I had a huge shireXandulisan who was saintly to hack in company he didnt hack alone though without resistance, he was from a trekking centre so simply not used to being alone, he didnt long rein atall ( wouldnt of been safe on a road) with him the sitting it out method got him going. but sitting it out isnt the answer really being stood on a road is not safe, especially if they decided to do it on a blind bend etc. With him Trotting worked alot, but I could tell when he was thinking of spinning for home or putting on the anchors. Sometimes it is just about trying to be one step ahead of them !