Found a solution online after much searching
1) spawn desired enemy/monster for pet (best to be in god mode (tgm))
2)enter console and click on pet, setscale (decimal variable eg: 0.5 or 2.3) to desirable size
3)stay in console and use command "kill" on the enemy whilst they are selected through clicking on them.
4) once dead exit console to confirm death, and then type "setplayerteammate 1" into the console after selecting there dead body through clicking
5) use command "resurrect" while the body is still selected, and they should rise up when you leave the console, and be friendly.
this worked for my SM Behemoth, and he is very docile now, hasnt even moved yet, and is friendly to the butler in my house too