I just said above that ancient sent with armor would live 1 PB and 1 bayo (hell, ancient runner lives 1 PB with 5% HP so imagine sentinel with its slightly bigger HP pool and armor if it chooses scattershot strain), and that the sent could just spit at the marine with buckshot neuro now that he's in point blank range and insta sleep him. With your cooldown being 3 seconds, you can afford to spit once from afar to slow him down, get in close, bait out or dodge a shot, then spit his face and then he's down. Weak slash damage doesn't matter at that point because the marine is asleep and you can take your sweet time doing whatever you want, including capturing. And no, sent does not need 25 slashes to kill a marine unless you're slashing a heavy armor marine in his chest. Aim head instead.
Also, why would you think a "buckshot neuro" is meant to be used from long range? Do you even play marine enough nowadays to notice that buckshot only does shit while PBing now, because the removal of the 20% accuracy buff in 1-2 tiles pretty much makes almost every weapon has a chance miss xeno in 1-2 tile range entirely, and doubly so for buckshot due to its innate shitty accuracy
Once again, the sentinel controls every variation that can happen in a 1v1 fight. The marine is at its mercy, not the other way around.
Carrier is still fine. The throw has been shit for a while now, ever since 2018, it's really not a "sudden" thing at all. It still serves the role of a mobile hugger reserve now that nest and egg can't be placed on the front line. When the queen is not on her ovi, they can't be placed at all. Shaman is a bit limited since it needs to be next to someone to buff them, and that should be buffed. But base carrier is still perfectly capable of doing its job, just takes a bit more work than before
I've been through some absolutely horrid meta for aliens like QF AP, tank after arti/OD module release along with buffs, PB, 4 tile buckshot, and way more while playing as both marines and xeno. The fact that you think current xeno is somehow weak is just laughable really. I'd love to see how you handle yourself in August 2018 after tackle and general stat nerf with overpowered tank still in the game at that point