I finally won my Long War 2 campaign (on Beginner, mind you) after ~71 hours of playtime (of which the final mission alone was almost three hours) so I guess it was a long war. Heh.
92 missions won, 1 lost because a sectopod/gatekeeper destroyed the objective turn 2.
26 flawless missions.
1127 (!) aliens killed.
22 soldiers lost (mostly rookies).
80% of shots were successful.
8.75 turns left on mission timers. I tend to be slow on missions.
86 soldiers that actually did stuff (of which ~25 saw regular combat)
163 days to first colonel, although IDK what this means with LW2.
1422 days wounded.
155 promotions earned.
16 colonels (yeah, this must mean master sergents/masters).
5 psi-op soldiers, (2 of which were masters, 1 was fairly low-rank, and the other two died on their first mission).
50 hack rewards earned.
17 robots hacked.
11 scientists, 11 engineers.
Days to:
Magnetic weapons: 162
Beam weapons: 375
Plated armor: 93
Powered armor: 334
Alien Encryption: 184
1 Radio relay built.
No facilities sabotaged (although in reality I blew up two so this must be bugged).
Supplies collected from supply depots: 5749
Supplied earned from black market: 648
Intel collected: 2125
Intel paid to black market: 540.
Victory date: May 28th 2036 (i.e. a year and three months in).
Some things I learned:
Anything that does guaranteed damage - grenades, psi soldiers, shinobis, various perks - is good because you can plan better around them.
Anything that does damage to multiple enemies at once is good: assorted late-game gunner perks (saturation fire and iron curtain), Reaper (one of my Shinobis personally made over 10% of my alien kills), face-off (pistol perks are ridiculous in general, but face-off lets you do upwards of 50 damage with one soldier in one turn; my soldier with the second largest number of kills was a pistol-wielder), technical stuff in general, etc. The best perks/abilities like this are the ones that reload after a few turns, but techicals are still useful because their abilities have a large AoE and destroy terrain or burn things.
If there's no timer, end every turn on overwatch and try to make the enemy spot you on their turn so you get a free shot at them. I hear that this is different at high difficulties because the aliens will sometimes shoot on their first turn, but overwatch still lets you shoot twice in a row.
I was a bit slow with my campaign, but that's because I was getting used to LW2. When I next get a chance to play a LW2 campaign, I'll try to have more than three squads in my rotation and I'll try to complete more missions (I started skipping them because I didn't care for what they had, but then I was short on Elerium cores and similar loot).