Please consider this Kabam...
A suggestion regarding the new arenas:
Personally using 5 and 6 stars in previous 4* and 5* featured I hit all milestones and got 270 units. However now I can put 17 mil. in both combined out of 33 mil. My unit earning from higher rarities have been reduced as now I would get 200 or 225 out of 360. I am not talking about 4* nexus arena here bcoz it is even more complicated bcoz of clubbing of three arenas in it.
My recommendation would be making 10.5 mil the last milestone in both arenas and putting the rewards of the new last 3 milestones in the 12 milestones that would remain.
In this way people like me with intermediate rosters(27 six stars) still won't get all milestones without spending units (lol spend units to earn units?) and 5 mil from earlier cumulative 16 mil to new 21 mil would be substantial.