@rootakye Read this, read it again, then one more time for measure. TFP is absolutely correct on everything he said here, to the point where I have nothing more to add other than to agree.
My PT test is a 1.5 mile run, not a 3, but with even that distance I find that 400m intervals help amazingly, but much shorter than that and I start to lose benefit. Having had to do the marine PFT a couple times, 800m and 1 mile intervals were my bread and butter for increasing time, with longer 3-5 mile runs at a tough but manageable pace twice a week done to get my body used to the mileage. It helps, and you do not want to be the slowest man on a run. Showing up maxing is a great goal, and will go a long way to help you out. Make that your main priority, with other weightlifting goals a secondary goal, not the other way around.
In terms of “tactical fitness” (I can’t think of a better way to describe what we are talking about, but I hate myself everytime I say this), look at Alpha’s old logs on here. He has some from when he was doing counter-terrorism work, only time I’ve seen a man with a 500lb bench who could still run sub 7 miles.