If I can find the people and I have time, I will train squared off with my Uke with another 1 or 2 people holding on his belt to keep him standing as I enter for Harai. I have still been known to know 3 people down with it. If I can't find the people to do it, or people don't want to waste the time bothering, then I will just take whoever I can find that is up for it and throw them. There was a time when I was in a rotation with 3 people working as uke, but their ukemi was just not good enough to handle more than 1 or 2 throws.
When I was training at UL in Lafayette, we even had a nice crash pad, but they were bitching that I was throwing a stright driving Harai and coming down on their chests. THEY on the other hand were throwing their Harai in a way that had them rolling out and not landing on Uke at all... which is garbage for competition. You throw how you train, which means that if you train to roll out away from Uke, then that is how you're going to throw IN competition. I train to bury whoever I am playing against, and 9 times out of 10, if I hit you with Harai, you will remember it.
Obviously when I am practicng drills I will enter like 9 times and throw on 10... but that throw is 110% and chances are, unless you have someone holding you up, we're going to fall on most of those entrances. That's what happens with a straight driving Harai (Or any other throw for that matter). It's pretty much impossible to remain standing.