Default permissions for new files and directories follow the umask setting, but this is set per filesystem rather than per directory.
You really should be persevering with ACLs, this is exactly the type of situation they deal with. Rather than trying to re-invent the wheel, and probably ending up with a square one, it would be better to look at why ACLs don't do what you want.
Like most other software, setfacl does what you tell it to, not what you want it to, so post what you want, what you tried and what you actually got.
"Insanity: doing the same thing over and over again and expecting different results." (Albert Einstein)