Ahh so pretty low level. Yup shouldn't expect balance issues too much.
We generally do not play the higher levels. Maybe a left over from 3rd ed and it takes a while to level up in OSR games. Damage doesn't need to be 2d6+20 or so from a martial character to be effective.
Though I found the spell disruption rules as written, used adversarialy by the DM, could make wizards all but unplayable. Given fighters didn't have a defender mechanic, outside of a bottleneck defense, there was no way within the rules for melee PCs to pin down enemies and actually defend the squishies. In practice it seemed to come down to a "gentleman's agreement" where the players made an effort to defend the squishies, and the squishies weren't pursued and hacked down as literal wargaming tactics might seem to dictate.
Where this wasn't the case, I saw campaigns where few or no wizards survived, maybe the occasional fighter mage.
I strongly prefer practical and transparent rules to rules that are applied situationally due to their brutality. I hated having to question DMs in 1e and 2e days to try and deduce whether wizards were worth playing in that campaign or a waste of my time.
Though I found the spell disruption rules as written, used adversarialy by the DM, could make wizards all but unplayable. Given fighters didn't have a defender mechanic, outside of a bottleneck defense, there was no way within the rules for melee PCs to pin down enemies and actually defend the squishies. In practice it seemed to come down to a "gentleman's agreement" where the players made an effort to defend the squishies, and the squishies weren't pursued and hacked down as literal wargaming tactics might seem to dictate.
Where this wasn't the case, I saw campaigns where few or no wizards survived, maybe the occasional fighter mage.
I'm playing 2nd ed again and it is not that broken compared to 3rd ed. Percentile based strength is not coming back and some of the AD&D have ditched it as well. Castles and Crusades uses the BECMI modifiers for example, 13-15 is a +1 bonus,16-17 is +2 and 18 is +3.
I think a cleaned up d20 ized 2nd ed with optional feats could be fun. Use tweaked 3rd ed monsters probably toning down the ability scores and ACs in some cases.
That said, low levels were always dicey for anybody with less than a d10 hit die...and even some of them if you rolled 1st level HP.
We're going to look at 2e for balance mechanics? Really? Good grief, balance was so bad in 2e that it was ridiculous. The difference between two PC's just because of character generation could be night and day. A 1st level fighter in 2e, straight out of the PHB, could kill up to six HD creatures in a single round (not the first round, true, just the second). 18/percentile strength and weapon specs meant you had a minimum +5 to damage and double attacks every other round.
People tend to forget that 3e beefed up the monsters a whole lot. Most creatures got two or three times more HP going from 2e to 3e and doubled their damage as well.
3e, for all its higher level balance issues, is head and shoulders better balanced as a system than 2e was. That was the whole point.
3e was better at some aspects of balance... worse at others like the often aforementioned spellcaster issues. And since spellcaster issues are a big aspect of people's complaints at 3e, I would expect a better viewing of 2e's balance. The thief was pretty weak and had terrible saving throws, but the balance overall was, in many ways, quite good. I'm really not seeing the ridiculous badness of 2e's balance aside from some particular cases, particularly those introduced by the elf book and Skills and Powers.