First, let me say I have experience with several x-coms in the past, and usually found them doable or even easy.
At first it seemed this way for PP too(playing on veteran), but I have hit a difficulty spike. At any rate, it doesn't feel impossible to beat yet, though I noticed I have to reload missions in order to avoid having my strongest guys being killed off. Which I hate, as I despise save scumming.
Normally, in x-com, by this point I would have unlocked better weapons, however despite being able to research for all three factions and getting all kinds of new weapons, I have noticed that all these weapons do essentially the same amount of damage. There is no "stronger tier", at least, not yet.
Thus my question, will such weapons eventually be unlocked, or is this the best I will get? Do I really need to hit a single enemy 6 times(and all of the hits actually hitting) to kill it throughout the rest of the campaign?
p.s.: forgot to mention, I have disabled all DLCs that came with the game