That's how the map works - in the first half of the map they aren't on the map yet but loose health - you can increase their health by destroying key objectives. After a while they spawn on the map and will be controlled by one player.
That has always been the case (and the intended way to counter them).
Lost Reaver has been fixed, so that he attacks you as he should, and iirc some Lost Wanderers were replaced with Crawlers. Maybe you just were lucky and pulled easy ones.
I personally don't think that this is a good idea. Beating a 9 very fast does not neccesarrily mean that you can beat most 10s. Also, you need a good team in order to beat a 9 in sub 10min, which most players just don't have. And you can be qualified for 10s without having 3 speedrunner friends. This would gatekeep the vast majority out of ever trying the achievement.
I need to take a close look tomorrow, but I think it also didn't count for me 😕
I played a lot of nature units in King's Ridge expert but progress for nature cards daily only started when I played an rpve 9 afterwards.
It is probably this way, because it would break PvP balance if it was the other way around. Maybe one of the PvP balancers can elaborate 🙂
Another alternative to Wrathblades would be to use Witchclaws or Dreadcharger.
They are not entirely unregulated - The maps for the achievements have to be featured maps, which are checked by staff members and only after receiving the staff's seal of approval they get the featured status.
Iirc, the idea was to have the Bandit and Raven units be different archetypes.
Maybe @WindHunter can elaborate (I think he is busy with patch preparations though).