A short tight lead - often triggers aggression in some dogs because they equate that with being unable to flee. Ie they don't realise they can back off if the lead is tight. They think their choice to avoid is gone, so they choose fight.
A short loose lead maybe - but then the human is very close and that can trigger aggression too ie I have to protect my human / resource.
So I prefer not to let a greeting happen with a dog that is clearly so stiff and upright before they even get into nose touch range. I don't know why so many people will let their clueless dog greet one that is clearly upset and in an aggressive pose, ie very stiff and focussed on the approaching dogs with not one "I'm friendly no threat" signal. Or no mirroring of the other dog's "I'm friendly no threat signals".