My reasoning:
Tech needs to be 18 or you're using a crappy store legendary instead of one of the iconic katanas. Probably Jinchu-Maru, then you can rely on Kerenzikov for all your slo-mo and use a Berserk OS instead of Sandevistan.
Reflexes has to be 18 for the best Kerenzikov+Nanorelays (and 16+ for Microvibration Generator, since epic Dense Marrow isn't actually in the game).
Body 18 is required to use the iconic Zetatech Berserk, plus Second Heart (16), Adrenaline Booster, and Bioconductor.
Leaves 12-14 for Cool and the unavoidable 3 in Int.
The problem is youre coming at this as a melee sword build. I can use whatever the fuck I want to use, pistols, ar, shotty, sword bat, whatever I want to use that day without a respec or reroll.
Reflex 18, useless because I dont use the Kerenzikov, like I said I use the Maneuvering System that gives you dodge while in mid air so I can glitch and run around like superman at 1000 mph and it only requires 14 reflex. Besides I dont like those dodge kerenzikovs anyway even if they fixed the bunny hop speed jump glitch. For melee I like that other implant, Zatech Sandevistan or whatever the fuck as your OS, that you hit E and time slows x amount for x seconds. Right now looking at my dude, I have a green one equipped that slows time to 75% for 8 seconds, which is plenty of time to sword a whole camp or at least most of them before they even have a chance to react. I suggest you try it over the useless berserk. But I have seen other better ones that slow time to 60% and last like 20 seconds or some stupid broken shit. And in 20 seconds you can pretty much kill a whole camp easy. Thats a way better mod than the Krenzikovs. I can do it when I want, not while im dodging. Which feels awkward to me.
And again cool 20 for merciless which gives flat 10% crit chance and 25% crit dmg, and every point you spend in it it raises crit chance by another 1% and 3% crit dmg which works for ALL WEAPON TYPES not just pistol or sword, or whatever. Plus it saves you points in other trees because you have crit chance and crit dmg covered.
You dont need berserk when your crit chance is already 100% from Cold Blood Merciless + clothes and other basic sources. Not just for your sword, but for ALL WEAPONS.
Body 16 is all thats needed for the one implant that revives you upon death. (Not that you die past lve 20 lol) Thats the BIS IMO that relies on Body. But were theo crafting the perfect dude if the game WAS hard right?
Tech 18 is a given for the iconic crafting at 50, youre just gimping yourself by not crafting all those lovely lv 50 legendary iconics which are the best weapons in game.
Anyway thats just my take on it, play what you want though the game is easy enough that none of this shit is necessary anyway right now.