warrior needs hamstring (snare) badly

Procs too!

https://everquest.allakhazam.com/db/item.html?item=303

I use something like this besides "Kunzar Ku'juch".

Glaive of Marltek
https://everquest.allakhazam.com/db/item.html?item=26033

Silken Whip of Ensnaring
https://everquest.allakhazam.com/db/item.html?item=341

Ball of Burlap Yarn
https://everquest.allakhazam.com/db/item.html?item=6574

Lack of utility and versatility is definitely a class-defining attribute of the warrior (along with the cleric, rogue, berserker and wizard classes). It's a game-design decision that most games have evolved beyond. Warriors are dependent on other classes for utility and healing, but provide best-in-class mitigation. Choosing it is choosing to be the tip of the spear when it comes to group and raid play, while being ineffective outside a group or raid.

I'd recommend playing a shadowknight, like you're planning on doing.

At will snare on a non-spell/song using class before level 70 really does break the class at those levels, and in facts makes them into a completely different class.

Enchanters get root at level 6 and Clerics get root at level 7. There were alternatives for your group, but you chose to ignore them, because they were not ideal is all I can guess. Countless groups did perfectly fine without having snare in the original game and early expansions. Pulling another before the targeted mob starts to run or rooting them are both valid viable solutions.

Warriors will get these effects via weapon procs, I used to keep a full bag (when bags were smaller obviously) of proc weapons for snare and slow and other things.

In addition to roots, CLR gets stun at L2 and ENC gets stun at L3.

This right here is the winner. Just stun & root them from the Cleric and Enchanter.