Color me stupid, but I can’t see how stand your ground applies at all in the case. You’re certainly unable to retreat when you are pinned on the ground with an assailant trying to smash your head on a curb!
Before, away from your home or business you had a duty to retreat from an attack before using deadly force. If you successfully defended yourself you'd have to establish that you tried to retreat or could not.
Even under SYG you have to establish that you were in fear of death or serious bodily injury to use deadly force. You are allowed to meet force with force but it has to be relative. You cannot shoot the guy throwing marshmallows at you even if its technically an assault.
More than that though it provides for IMMUNITY from arrest, prosecution AND civil liability if you establish a valid self defense.
Thus you can avoid a trial at the whim of who knows what jury and if your charge(s) are dismissed the family/powers that be cannot sue you for damages.
Under common law you've always had the right to self defense but under case law and statutes the retreat rule was a factor, you'd almost always end up in trial as a defendant and despite your "presumption of innocence" a lot of jurors tend towards the "If he's not guilty why was he arrested?" mentality.
In short, in Florida, if you can establish self defense then the immunity provisions apply, there is no duty to retreat and you can ideally get charges dismissed (if you are arrested at all) without facing a trial.
Also in an pre-trial SYG motion you need only establish by a preponderance of the evidence (50% + 1) that self defense principles are met as opposed to the prosecution having to prove your guilt beyond a reasonable doubt. Pre-trial the burden of proof is on the defendant (preponderance), at trial its on the prosecutor (reasonable doubt).
Clear as mud? ;-)