I’m not quite sure if the logic train here. I don’t understand how changes to the MU from 1st to 3rd are related to Clerics/Druids?
Also, I disagree with what wgat I think I read as indication that D&D went from something “balanced” at 1st level to unbalanced in 3rd?
I don’t think 1e, 2e or anything flavor of 3e were ever “balanced”.
4E may very well have shown what a highly “balanced” rule set would be, but it was about as interesting as unseasoned gruel.
I have no idea about 5E, but it’s clearly a popular ruleset.
Let me explain in more details.
1ed was extremely well balanced because it was not balanced! Paradoxal, yes. But true nonetheless. Unfortunately, the "big" picture was lost at some point.
With all limitations put on the casters. Martial classes were strong in the beginning but declined as they rose in levels in favors of casters.
Casters were weak in the beginning (obviously) but got really powerful spells as they rose in levels. Yet, this was balanced again for long casting times. Everything was either check and counter check against the fighter and the thief.
Even the stats were a balancing factor. Only fighter type could hope for +3hp/hd or more con bonus. Other classes were limited to +2.
This limited the hp of casters so that it was possible for a martial character or a thief to slay a caster in one round. If the character could get to the caster.
Weapon speed factor and damage vs large opponents were important. As a they would give each weapon a different use and feel. The mighty two handed sword would do 3d6 dmg vs a large opponent but was slow as hell. Almost useless to stop a caster. But against a giant, a dragon or anything bigger than a man, ho boy was it unbeatable. The long sword was faster but did less damage. The middle ground was the bastard sword but finding one that was magical was not an easy task.
The goal was to do a lot of damage early against large opponent and to stop casters from casting. The rogue, when unseen, could get to the caster but it might take a few critical rounds. But once in place, 5x the damage of a +3 dagger/short sword with gauntlets of ogre strength would make sure that the caster would die in one hit. Fast weapons were used against casters to prevent them from casting. And the ultimate mage killer was... the monk. The only character that was fast enough to get to the casters, make zounds of attacks at 8d4 each... and each of those could stun or kill any target outright if the save was not made. Bless spells, chants and prayers were particularly effective on monks. But monks had relatively low hp and had to fight to rise in levels.
Everything was playtested and balanced for the long run. The stronger you were from the start, the slower was your power curve as you rose in levels. And the reverse was true. The weaker you were at the start, the faster your power curve. There were a few exceptions:
Paladins were balanced with their stat requirements. It was hard to make one. Again, by just allowing someone to make a paladin and give him the missing stat (usually charisma), it led to all kinds of abuses and to the ultimate paladin nerf: The Lawful Stupid.
Monks were also a bit balanced but really got strong around level 7. It was also at this level that they had to fight their way through. Their stat requirements were also a limiting factor but when a monk was in the party, I knew that enemy casters were done for.
Ranger were less affected by stat requirements but these requirements made them a bit hard to come by. Their strength was against humanoids and giants and it showed.
The real gem was the druids. Although the requirements were not as harsh as the paladin, their versatility was almost stupid. Druids were good everywhere even in caves and dungeons. Of course they had to carry mistletoe and seeds for many of their spells but it was often worth it. At high level it was almost impossible to kill one in a forest. Their main limiting factor was the fact that they had to fight to get to high level.
Again unfortunately, the "big" picture was lost at some point. As new players go around, the reasons why such thing were decided were forgotten. Never at my table have I heard that 1ed was not balanced. It was, but not from the start. It was understood that each classes would be better depending on the level they were at. But new players wanted to be as strong as anyone else from the start. 2nd edition was just a toned downed version of 1ed and many old players did not bothered with it. jBut it was a "popular" enough edition to keep the hobby alive and evolving. It did away with some of the harsh restrictions of 1ed but not all. The Lawful Stupid of 1ed was still a thing but since the paladin was not that restrictive, it slowly went away (at least, I saw a lot less lawful stupid in 2nd edtion than in 1ed).
3.xed was the first edition in which just about everyone was relatively on par from the beginning. It was not a perfect balance but it was a beginning. Relatively sooning, it proved to be but a wall of smoke as it was discovered the power of casters were unchecked for the first time in D&D. The arrival of the 5mwd and the Codzila created a lot of dissent. From level 7 and up, martial classes were there only so that the casters could do their stuff. The higher the level, the stronger this effect was. Enough that a new edition came relatively fast (3.5) and it didn't correct the problem. Pathfinder tried to correct it too but the success was, underwhelming?
4ed was the edition every "balance from the start" players dreamt of. Unfortunately, it was not well received. Although I was a fan, the edition suffered from the: "all things must be balanced" and it felt too MMORPG for a lot of people. But it had really good ideas and some of the best ideas of 4ed carried over to 5ed.
5ed is a throw back to 1ed with a bit of 4ed mixed in. Again, balance is now relative but in the long run, no classes outshine the others. 5ed does have its own problems but the limitations that have been put serve their purposes as they were intended.