Permission & Requirements Notice
As Attacko's Daedra 2's assets are open use, the original mod is not required as this mod contains all the assets for the Behemoths. However, I recommend you support and endorse Attacko's work as without his mod, this one could not have been created.

SkyPatcher is required for Behemoth distribution into level lists and spells.

Attacko's Daedra Integration and Rebalance Series
"Attacko's Daedra 2" is a great, relatively new creature mod with very impressive and beautifully designed models.
However, in the original mod, many of the creatures are either overpowered or are poorly integrated into the world (many are just in random sections of wilderness outside towns). Attacko's Daedra Integration and Rebalance is my series of mods that aims to fix that by rebalancing the creatures to be closer to what you would find in vanilla as well as integrating them into the world in a lore-friendly way. Additionally, full Requiem support will be offered through my mod, Requiem - Auto NPC Patcher. 
Daedra Covered so far:
Abhorrent Behemoth
Anthropoid Daedroth
Bipedal Charyboid
Fire-Tounged Daedroths
Sulking Twilight

See Xtudo's texture fixes for Attacko's Daedra too!

Creature: Abhorrent Behemoth

Rebalancing
Abhorrent Behemoths have been split into a lesser and greater form,.
Lesser Behemoths, referred to as just "Behemoths" in-game, are now on par with Frost Atronachs health and size-wise but have stronger attacks. 
To compensate for this, their movements are slower than Frost Atronachs.

Greater Behemoths, referred to as "Abhorrent Behemoths" in-game, are much larger than lesser Behemoths and now have health and damage output similar to Mammoths.

Requiem-Specific Rebalancing
In addition to what has been stated above, Behemoth power attacks now apply knockdown effects and they have been given Armor Penetration perks.
To compensate for these additions, on top of being slower, they have reduced armor relative to Frost Atronachs.

Integration
Spells to conjure lesser Behemoths have been distributed to Forsworn mages and Madanach (Customizable in FOMOD). Requires SkyPatcher.
In addition, lesser Behemoths have been added to Atronach level lists at the same level as Frost Atronachs. Requires SkyPatcher.

Behemoths can be found in areas associated with Forsworn and Daedra.
Greater Behemoths can be found in Skyrim in the following locations:
Boethia's Shrine
Bthardamz
Deepwood Redoubt
Fallowstone Cave
Nightcaller Temple.
Red Eagle Redoubt
Rimerock Burrow


Requiem Support

This series is designed with Requiem support in mind through Requiem - Auto NPC Patcher, a patcher I wrote that can automatically adjust the stats of any NPC from any mod to be in line with requiems balancing. 
To use this mod for Requiem, first install Requiem - Auto NPC Patcher and all its requirements. 
Then download and install the "Requiem" version of the main file of this mod. After enabling "AbhorrentBehemoths_Integration.esp", you will first run the Requiem for the Indifferent patcher and, afterwards, run Requiem - Auto NPC Patcher.
Details on how to patch any mod with Requiem - Auto NPC Patcher are included on its nexus page.