Amir Johnson is very underrated, from what I've seen he is a greg monroe type with better defense. that contract looks big now but will look much better next year than paying the max for monroe. He will be a nice compliment to sully/olynyk.
The Jerebko contract seems too much, he is at best the 8th or 9th guy, id rather see that money go towards a corey brewer or help resign crowder.