A standard action to make it act makes it sound pretty worthless for much beyond soaking damage and flanking. This whole "conservation of actions" is a pile of garbage. Just because Timestop was busted and they screwed up and made a level 1 druid animal companions better than a level 1 fighter in 3.5E doesn't mean you have to gimp everything in 4E. In 4E if the mobs are being out-actioned, just bring in more minions.
You sure you're not confusing "balance" for "fun".
To me it's pretty clear that any power that adds allies to the fight must either add crappy allies indeed, or effectively replace your own character in the fight.
"Balance" doesn't have anything to do with the opposition. It's the balance vs. the other characters' options we're talking about.
In other games it might be perfectly fine to have wizards and druids to occasionally cast spells that are much more powerful than a fighter's tricks, all in the best interests of the group.
Not so in 4E. And this brings us back to the fact that a summoning spell either must summon a feeble inconsequential critter (if the summoner can continue to act unhindered) or more or less a copy of the summoner (if the original is held up controlling the summonee)*.
*) And still this copy needs to suck compared to the original or it's overwhelmingly powerful. Or any damage needs to transfer across to the original, which raises the question of "why bother in the first place?"
Now, you might think I'm altogether disagreeing with you. But I'm not.
Because I
do agree this is wrong.
Not because of balance issues, but because of fun issues. I completely agree it isn't much fun if all your allies need to suck badly. However, I think that is the price you must pay to keep things balanced.
Essentially, any power that brings in allies must choose between being balanced or being fun.
Put otherwise, don't play a summoner druid/wizard in a game such as 4E. You need a game of the traditional paradigm, where spellcasters were allowed a few big bangs a day. Bangs, that is, bigger than anything other characters could do.
"Real" summoning needs, by definition, to be more powerful than any ordinary power of the same level/occurrence. And I'm not holding my breath for a 4E class that does this.