When I looked at the detail list for the Family, it only had 2 minions and one lieutenant in the level 30-35 range then a bit more in the 36-40 range.
I'm not sure why my test with a level 35 character didn't spawn the level 35 mobs over and over but I'll chalk it up to experience.
I modified my mission to use Council instead (which is 1-54) and will test it this evening. I expect it'll work fine now.
Lesson learned - be sure to check the deail list of any mob you intend to use and not just trust the level range given.
I created a new villain arc. It uses all standard mobs and custom bosses. I used mostly level 1-54 groups but in the final mission I also used the Family for a little variety and for story purposes.
When I test this mission with a level 35 character all the Family spawns are level 30. Only the mission objective spawns (not Family) were of the appropriate levels. I could literally walk right through it fighting only the required encounters.
When I test with a level 24 character everything is great.
It's all a bit frustrating and completely opposite of the level+12 problems I was having in a different arc.
Is there some gap in the Family group, despite the description saying they are 5-40? Any suggestions for an alternate group with a similar theme and wide level range?