Granted, 5 months is a lot of time.
Nergal (Zombie's Life, Urban Demons) has the artists he has commissioned as you said and per update IIRC there were maybe 3 scenes, correct me if I'm wrong.
Alansya Chronicles is again, a commissioned artist with around 4 scenes per update.
Now I'm not bashing either of these because the quality has always been on point and obviously, frequent updates is always a bonus.
PandP on the other hand is just the two of them (is it two of them? Again correct me if I'm wrong) doing 3DCG which is obviously time consuming with posing and the like as well as doing the animations which I can only assume is a pain in the ass to get looking as good as it does.
And then comes the coding and the dialogue (of which English isn't their mother tongue I'm pretty sure). And coding is a landmine in of itself.
Anyway, my point being that as far as I understand the differences between Nergal, HeavenStudios and PandP, comparing the two to PandP is a bit uneven considering.
Only one I'm unsure of is Humbling experience but that is also 3DCG isn't it? Depending on how they work could be a fair comparison to PandP but again, I haven't looked into Humbling so I wouldn't know.
I am agreeing however, that communication has been poor, as in, dad left at childbirth poor.
Edit:Also, if I understand their recent comments correctly, the next update includes 300 cgs and 14 animations so, there is also that