There is only one unit I totally loath in this game and that is the Kaukopartio squads as I have run onto them twice the first time was with my 4 total squads of roughly 3, 8 men Vets and the 12 man free squad, heavy, mortar with spotter, sniper, and a MMG team with a dog mine and Ampulomet/ Molotov launcher, with a BA-10 and Valentine X lend lease British infantry tank with medium AT gun and coaxial MMG all under a regular 2nd Lt. And after 3 rounds it was like I just wasn't hitting them with anything more than spit balls if I took small arms against them as they just didn't seem to die, due to that medical kit trait they sport and being vets they only die on a 5 or 6!!!!!! But then they get to roll a saving roll and every 6 it was like you didn't even hit them to begin with. Other than the 3, 8 man Vets and sniper everything else on my list was regular. The 2 Soviet units that do a lot of damage against them is the Ampulomet and heavy mortar due to the 2 and 3 inch template and HE profiles they each have. The second time though I swapped the sniper, MMG team, dog mine and Valentine for the KV-2 with coaxial flamethrower with another 8 man vet squad with mostly rifles and AT grenades when I found out a few of these groups was on my opponents list. My motto with the Kaukopartio is when in doubt kill it with fire, and if you are still in doubt use more fire until there is only ash. And if you run out of fuel that is what that big old M-10 152mm howitzer is for. But yes I highly highly hate these squads with a passion as I know if they can dig into an objective I am going to have a real hard and long slug fest with probably a few units being deleted before the start of round 5.
Kaukopartio are definitely worth it. They do exactly what you said, they take out a big enemy unit then cause massive panic and distraction. Would be interested to see how many tournaments you are winning.