Lumen Dissipation-600k closer vs. 1000k further away

I have been searching for answers regarding lumen dissipation to resolve the decision of utilizing 1000k hps at a greater distance from canopy vs. 600k hps at closer distance to canopy. From the chart provided, it stands to reason that a 600k at 12" above canopy provides superior lume ns to that of 1000k at the customary 18-24". Is there something I am not computing here?

I currently run 1000k 's and am looking for options that would make for more effective cooling without compromising light quality. Sorry if this is a high repeat question, I couldn't find much on it. Thanks for any feedback yall.

See the biggest issue with these 1Kw lights is the heat, the 600w is a finely balanced light with considerably less heat than the 1Kw lights, for this reason the 600w HPS is the same as an AK47, multi use multi adaptable, the 600w has 66k lux at 8 inches versus the 1Kw at 65k lux at 10 inches, then theres is the lux/lumen per watt ratio that many guys like to spit about now ....lol
When Caligrower made the charts he didn't take into account of growers using cool tubes and such, but just the standard vent extraction typical of grow rooms back in the mid 90's

Thanks Vos...it seems quite obvious 600w at close range would be a more efficient and effective choice. Yet where I am in the Sierras, one might be ostracized for such talk. I am very open for any further input or contrary viewpoints.