...ummm. Useless armor and weapons?
I play on the highest difficulty setting (which TFC largely ignores, almost nothing scales with difficulty setting in that mod), and yes, I avoid combat like the plague at the start and hide like a little girl. Then I make a beeline for bronze (or equivalent), and craft a full set of armor and weapons from that. From then on I'm pretty much invincible. I can stand there and take hits like it was vanilla on easy setting, while mobs die in 2-3 hits. And that's just tier 2 out of 6.
Your perception probably stems from what I mentioned above: player skill and knowledge matters far above anything. For instance, not every weapon does equal damage against every mob. The correct weapon for the job may kill something in 2 hits, while the wrong one (of the exact same quality) may take 10 or more. Basically, if you're trying to kill a skeleton with javelins, you're going to have a Bad Time(tm), and even a sword won't do full damage. Use a mace instead and watch those bones shatter.
As for armor being useless, you probably just don't have any HP to make use of it. Your total HP in TFC is dependant on keeping all your nutrition meters up by eating a large variety of foods. I mean yes, you can survive perfectly fine by eating nothing but apples, but you'll be running around with just 20% of the HP of a person who goes through the trouble of farming and breeding all the things. Then it'll be no surprise when that enderman over there two-shots you even through armor