Will have a look at it when I have the time.
I've got time!
Okay, it still looks way more complicated than it needs to be, but to each their own.
If you're lowering the CON to 14 (+2) it'll have
Hit Points 55 (10d6 + 20), not the old version's 65 hit points.
The Pathfinder version of
Bleed does not stack. That is, if a creature has three 1d6 bleed wounds they roll 3d6 but only take the highest dice damage.
Your version appears to be cumulative but with lower damage, so if it has three bleeding wounds a creature would take 3d4 damage.
It's important to say
when the target takes the bleeding damage, the main choices being "at the start of each of the wounded creature's turns" or "at the end of each of the wounded creature's turns."
EDIT: Just realized that the latter is the only way to give a wounded creature with only a hit point or two left a chance to stop themselves bleeding to death, so I'm amending the Cleon Grassling to have end of turn bleeding. :ENDEDIT
Finally, with Nimble Escape, Pack Tactics, several Resistances and a minimum DPR of 40 [four claws for 30 (4d6 + 16) slashing plus 10 (4d4) from bleeding) I reckon this version is nastier than Challenge 3.
The CR Calculator says it's anything from CR 4 to CR 6 depending on what Monster Features I flag for its abilities.