Okay, I've updated this thing. I saw the agreement about ditching Fighting Style and giving them something else. I also saw the suggestion to shift the Combat Master ability down to 3rd, but that seemed rather powerful to me. Even with Swashbuckler there is a restriction that early, and for my Divine Sleuth subclass, I limited it to fiends and undead.
Anyway, here's the revised Warrior
Rogue: Warrior
It is not uncommon for rogues to appear in the military. Many are scouts, spies, saboteurs, and assassins, but not many have a large place on the battlefield. You do. You have honed your craft to a point where you can take place in the front line, next to the knights and cavaliers.
Martial Finesse
At 3rd level, you have trained with certain weapons to the point of mastery. Choose one melee weapon that does not have the heavy or two handed property. You gain proficiency with that weapon, and it counts as a finesse weapon for you. You get to choose another weapon at 9th, 13th, and 17th level.
If the weapon has the versatile property, it only counts as a finesse weapon if wielded in one hand.
Bonus Proficiency
At 3rd level, you gain proficiency in Medium Armor and Shields
Armored Shadow
By 9th level, you have become accustomed to armor heavier than most other rogues are used to. Additionally, the Dexterity cap on medium armor increases by 1 for you, and medium armor does not impose disadvantage on stealth.
Additionally, you gain proficiency in the Athletics skill, if you are not already, and you double your proficiency bonus for any Athletics checks you make.
Precise Strike
At 13th level, you have learned how to find and exploit weak points in your foe. While you are wielding a finesse or ranged weapon, you roll a critical hit on a 19 or 20.
Combat Master
By 17th level, you no longer need help to distract your enemy. You do not require an ally within 5ft of your target in order to use sneak attack.