Terms like the economy of actions are new and useful tools for considering how to run or shape a game.
However to my mind they took the wrong apporach with 4e. I don't want "Equality for all, in all ways' as a religeon ala 'The Sirens of Titan.' More useful is a toolkit approach where the economy of actions is discussed and a range of options for dealing with it is presented from the lesse faire capitalism approach of standard 3e where casters can summon almost anything, and the buff/polymorph them, to option that prevent buffing of summons, summoning from a fixed list like some of the options in Unearthed Arcana, to simple tips like having all summons pre-written on 3x5 cards, to striping summoning out entirely.
Then each table can sculpt the game to suit their need.
Can a single player who effectively has 5 characters a problem? It can be, it might not for some. I've played a shaper psion who was an astral construct summoning god in 3.0. While I suspect he was more powerful than the rest of the party put together he did not dominate either the fights or table time because I would get everything worked out and rolled up before my turn came around and could just spit out he does this, that one does that and my shaper vitrifies that guy.
OTOH I played a Cleric with some FR PrC that gave him a gaggle of mephit following him around. I did feel guilty about sucking up table time with him, because all the numbers kept shifting with various buffs, plus the little bastards were fragile enough that I had to take a lot of care not to get them geeked.