All fights are winnable but your stats and skills play a big role, of course. So far everything you mentioned - high STR, axe and shield, heavy armor, focus on combat, etc sounds pretty good to me. What are your axe and block skills? DEX and PER?
STR: 9
DEX: 8
CON: 8
PER: 6
INT: 5
CHA: 4 (Not really sure what that 4 is doing for me as I fail all checks. I'm sure it helps with merchant prices or some shit, but that doesn't matter much in most RPGs because loot is usually plentiful enough. It may be worth dropping it to 1 for more PER if I reroll)
AXE: Level 6 Rating 63
Dagger: Level 2 Rating 24 (Planning to put more points into this as I it only costs 2 ap to attack and I often have 2 AP left over)
Block: Level 4 rating 58
Crit: Level 2 Rating 30
I mostly just use quick attacks, except against heavily armored dudes, because I can get in 2 hits with usually 70ish % to hit and then burn my remaining 2 points trying to hit with a dagger (I almost always miss with that, but that's expected until I train it more). Do leftover action points do anything btw? Like boost my AC or something? Or should I always try to use all of them each round?
Gear:
Auxiliary Helmet (bronze)
Lorica Segmentata (bronze)
Cavalry shield
Skeggox (bronze)
Sefet (Iron) - on belt
Also how do you flee combat when you know you are going to die? I tried running from the soldiers at the mine but I reached the edge of the map and there was no transition to the worldmap like there would be in say, Fallout. I just got surrounded there and died, stuck against the edge of the map. I didn't try to fast travel while still in combat but I'm gonna go ahead and guess you can't do that. Apologies if that was covered in the tutorial.
As an aside, I'd like to offer a belated congratulations on releasing the game. I wasn't around here when it came out, but I followed it's development for several years before drifting away. I couldn't fucking believe it when I saw it on Steam. It made me genuinely happy for you and everyone here that supported Iron Tower to see it get a release, because I didn't think it ever would. It must be great to have that monkey off your back.