I have been waiting for this moment for a long time and I'm stoked for monster mash lists
I love monsters, and Thunder Lizards has been my favorite list since the new battletome came out. But I still hate what they're doing to melee infantry and non-monster units in general. The buffs to monsters are a needed addition, absolutely gutting most battleline, and literally nerfing melee battleline to the ground, was 1000% *NOT* needed.
Of course it's GW and they want to make money, but clearly the new edition is based on forcing everyone to drop the horde lists they were running before and start buying all the big, expensive monsters and elite units like Kroxigors or Varanguard that can function in MSU but cost $50-$100 for a unit of 5 or 6...
So just to clarify, here's all the hits that melee-based infantry and cavalry units are taking right now:
1: Coherency rules mean you can't deploy in a line, you must go double-ranked at the minimum. So even with MSU you will have a hard time screening effectively.
2: Coherency rules also mean you can't wrap enemy units anymore. This is going to kill their damage output, making them even less worth taking. If you don't have a 2" weapon range, you're SOL.
3: Reinforcement rules mean that most basic battleline units that come in MSU of 10 but can go up to 40 can now only go up to 30, and it's only possible to have a maximum of 2 units at that size because you have a max of 4 RP and it costs 1 RP for each increment of 10. Skaven, Gitz, and any other faction with battleline that starts at MSU 20 can still go up to 60 for 2 RP. So they can still field double the amount of infantry that most anyone else can, but factions like Seraphon, Khorne, Nurgle, DOK, STD or anyone else with good, cheap infantry who sometimes liked to field 80-120 of them can no longer do so at all. Again, most factions are MAXED at 2 "hordes" of 30 where they used to be able to take as many as they had points for.
TL,DR: GW doesn't want you running hordes anymore. You can't bring many and they are much less effective in combat.
Shooting hasn't really gotten nerfed at all, other than also being subjected to the unit size limit. But unlike melee, there are actually buffs to shooting in 3e in the form of the overwatch CA and IMO, the smaller board size benefits shooting just as much if not more than melee because now it's even easier to have your targets in range.
I really was determined to be optimistic about 3e, especially with the early leaks. But the more stuff that comes out, the less I like it.