This is a pretty good side view shot of a stock Jeep Commander from the factory with no modifications - this is the normal factory OEM nose-down stance, which is typically with the front about 3 inches lower than the rear - give or take a half an inch.
I have to tell you SandDab, you & your friend of a friend have really made this far more complicated than it needs to be.
I understand that you needed transportation and you got it from a friend - and I'm sure budget was probably an issue.
But when you start making modifications to the suspension - specifically modifications that affect ride height, it's pretty important that you do it correctly - and all at once - meaning front and back at the same time.
I don't know why your friend of a friend had 2 1/2 inch spacers added in the front and did nothing in the rear - whatever his logic was - it was wrong.
All the leveling lifts you see that are advertised with larger spacers in the front, then in the rear, are correctly designed like that to compensate for the nose-down factory stance - that's why they are called leveling lifts.
It sounds to me like your Commander had the normal nose down factory stance - and you mistakenly thought that something was wrong, because you believed that the front of your Commander was sitting too low, when in fact - it had the normal, nose-down, factory stance.
And allow me clarify something else
- bad OEM factory front shock absorbers/struts have NOTHING to do with your ride height in the front - it will just affect the way your Commander rides - meaning it will take the bumps like crap. As far as the possibility of the factory springs being bad - the springs are designed to last the life of the vehicle, so, unless you have a very heavy engine (which the 4.7L is not) or your XK was used for a lot of heavy towing it's entire life (which is highly unlikely) the chances of your front springs being bad or damaged were pretty slim.
Replacing the factory front shock absorbers & springs with new coil-overs was fine - But putting 2 1/2 inch spacers in the front and doing nothing in the rear, was a mistake - your friend really screwed the pooch there.
So, how I see it, you have 2 options - the cheaper option (and NOT the way I would do it) would be to buy a set of 1 1/2 inch spacers and add them to the rear - and see how she sits - my guess is that would probably put you level - or extremely close to it.
If it were me, I would get the 2 inch Rough Country lift kit - which is a spacer, leveling lift kit - and have that kit installed, using all of Rough Country's components - meaning that you would have the 2 1/2 inch spacers that you previously had installed in the front removed, and have them replaced with the front spacers from the Rough Country lift kit.
And yes, of course you have to install the rear spacers from the Rough Country Kit too.
While you are at it - replace the rear shocks - because if you are still riding around with the original factory rear shocks at 220,000 miles, trust me - they're done.
You asked how to make it right - this is the proper way to do it.
This is the kit you would want to buy - it's only $170.00;
2in Suspension Lift Kit for Jeep Commander / WK Grand Cherokee  | Rough Country Suspension SystemsŪ
This is the most reputable and proven Jeep Commander spacer lift kit on the market.