Excellent question. What you’re really getting at is what’s known as “concurrent training,” which basically asks “how to we combine strength and endurance training such that we get maximum benefit from both without creating undue soreness/fatigue/conflicting responses/etc.” That really is the crux of training for tactical athletes because, as you mentioned, there is a need to be both strong and also enduring.
There are multiple ways to skin the cat here, but when I am prescribing strength workouts for my tactical athletes, I’m generally looking to focus on large, compound movements that give me the most bang for my buck. Think deadlifts, squats, presses, etc. Where I might differ from what you’re describing is that my weight prescriptions aren’t based off of % bodyweight; rather, I’ll use an autoregulation strategy like RPE to let the athlete’s readiness on a given day determine loading. For example: we might do 3 sets of 5 back squats at an 8/10 perceived effort (RPE). If the athlete feels good that day, an 8 out of 10 effort might be a heavier load than if the athlete feels under the weather.
The next question becomes one of volume management. Doing an excessive amount of unilateral, lighter-weight work without a clear purpose really just ends up taxing the same sort of aerobic/muscular endurance systems that we tax when we do long distance running or rucking. There is an important caveat here, though: unilateral work has it’s place in training…usually as accessory work that is specifically targeting an area of weakness, a strength imbalance, and injury, etc. We have to be very deliberate about this, though, because more often than not the biggest mistake I see guys make with their programming is generating a ton of “junk volume” with excessive unilateral work and/or lightweight bilateral work that isn’t really doing much.
So to kind of put a bow on it, what I’d say is this: if endurance is the priority, keep that at the forefront of your training–allocating more training time towards Zone 2 work and the occasional speed session if that is relevant to your job. With whatever training time/adaptation currency you have left, inject weight training that is intentional, appropriately heavy, and prescribed with just enough volume to move the needle without causing issues. Once you’ve addressed the two ends of the spectrum, fill in the gaps with unilateral/accessory work that is specifically prescribed to address areas of weakness. If you stay true to all of that, you should have no problem handling everything.
Hopefully that helps! If not, feel free to shoot me an email at firstname.lastname@example.org