After experiencing the difficulty spike in my 3 playthroughs since buying the game a week ago, and reading the multiple opinions on the forums, this is my take;
. The real issue is map size, combined with how many enemies there are, combined with how enemies activate.
Sure there is some class, enemy balancing to be done but it is not critical imo.
The real issue is that the game can easily spike to a situation where your guys are outnumbered/outgunned and tactics cannot save you. I am writing this as i come off a mission where my main squad is at lvl 5 (so mostly they have utility abilities and not yet the killer abilities like rageburst) and they are up against 12 enemies, one of them is a fire worm artillery alien.
Here is the problem, because of the hp/armor spike, my soldiers cannot solo kill an alien yet. So I have 5 soldiers, vs 11 aliens + 3 worms/turn, where i need 2 soldiers to kill 1 alien. Now why is this a problem? Well because the map is so tiny that by the end of turn 2 all of the aliens are on top of my soldiers. Plus worms. And also because all enemies on the map activate at the same time!
The enemies in theory should only attack you when they become “alert” but since the map is so tiny any move immediately exposes you. Not to mention there is cheating going on since aliens always move in your direction even before they see you…
. tiny map that does not allow tactical maneuvering
. outnumbered fights of 3 to 1 and maybe more
. enemies that require multiple soldiers to kill, but can kill you in one turn (without rageburst)
. all enemies on map activate immediately and zoom in on you (unless it is a scavenge mission with crates)
These factors in my opinion are the problem with combat. If i could maneuver around the map, if cover was a real thing (it isnt in this game), and pick my fights, it would be totally ok to have stronger enemies, and be outnumbered.
Make the maps bigger. Allow for aliens to be “pulled” in a tactical way instead of the zerg that it is now, and I guarantee the fights will now seem so unbalanced.
That is the thing that worked with XCOM/UFO defense, you could decide when/how/how many enemies you would engage if you used proper tactics.
I am confident this is easy to be fixed with the introduction of the DLCs and has the game expands.