What is the better lighting setup for me? should I go for Mixed spectrum or better penetration?

I have a 4x4 tent and both a 600 watt hps and a 400 watt hps/mh. I am downsizing to only using the tent as my flower room and I am wondering,
would it be better to run the 600 turned to say 75% with the metal halide in the 400 turned down to 75% or 50% to add spectrum?

or to use just the 600 at full power? and keep the penetration and advantage of 600 watts being the most efficient light per watt? What would you do in my scenario and why?

Also would it be worth running AC to cool the room its in enough to run both lights full power?

or if i replace my 240 cfm fan with a 6" inline or two and run lights and intake and exhaust separate instead of current passive intake do you think it would cool both lights enough to run full wattage?

Ambient temps are usually 70 or slightly under but in the coming hot colorado summer the room will sometimes creep up to 75, which makes things much harder to cool down.
but I really like the penetration of the 600 watt hps compared to the 400.

at full power do you think I would benefit from using two hps or using the MH in my 400 to get a mixed spectrum?

I care about final qulaity and yield equally, but does MH really increase resin production noticeably? and if so does the extra leafyness outweigh it? any replies from anyone with experience in mixed spectrums or similiar lighting situation are much appreciated. thanks in advance

just to clarify when i said temps creep up to 75, i mean outside of the tent in same room

I run a 4x4 with a 600, cooled with a 6" 440cfm pulling through a carbon filter with a passive intake and my temps run 6-8 degrees over ambient. It works well but a little more light is nice. If you add the 400 you will need a small ac to drop ambient a little bit. I would personally just run the 600 for the summer and run a 600hps/400mh when it cools down, works like a champ