sst20 vs xpg2 vs xpg3 vs SEOUL SZ5M2 vs alternatives

.

That table is irrelevant really.
First column in the model.
Second is manufacturers recommended max current.
Third doesn’t relate to the LED, maybe a MCPCB material recommendation but that would depend more on how much power you will be putting through the LED.
Fourth is subjective and only says the XP-G2 throws better then then XP-G3, which it does with all other things being equal.
Fifth column is subjective, says the SST-20 and XP-G3 are have more efficacy than the XP-G2 which is fair to say.

I think the throwiest LED for a 3A light, taking nothing else into consideration, will be the green White Flat 1.
But it has a 3030 footprint and is green, if you want white than a white White Flat 1 will be the throwiest.
If you need a 3535 footprint, or a specific colour temp, or a certain level of CRI etc it would be a different recommendation.

What are your requirements?