I guess you have to decide for yourself if you want to be the true alpha leader that your horse trusts and relies on in all situations and so follows willingly because it sees you as its leader
If you want to be the bully that you see as the alpha which is the horse the others run away from and avoid and would prefer not to follow but to be as far away from as possible
I have a 'bully' amongst my 'herd' of five and she is most definitely not the leader when it comes down to it. She may push the others away from food but she lacks confidence in 'scarey' situations and is totally dependant on the calm reliable passive alpha mare to give the lead - and when this mare wants what she wants she just walks quietly through and they all move away and let her - I have never once seen her attack another horse or even look mean, she just somehow commands respect - maybe because they all know in their own 'horsey way' that's she's the one they all rely on and so can't do without.
This should be a clip from a longer video where Mark Rashid explains very well how a herd actually works. Ignore the bit tacked on the end as not relevant.