I like it very much, actually. It does a wonderful job of representing a horde bringer druidic summoner. I'd like to see at least one other class do a good job of that as well, because Druid isn't exactly my go-to for summoner, thematically.
As for the "summon a big bastard and let it wail on things", more spells could do it, but I'd prefer a subclass with unique mechanics that really dovetail with controlling a single big thing. A druid might burn wild shape uses to bring forth a great guardian, or a warlock might get an even more improved find familiar, that stacks in benefits with Pact of The Chain but can be used with any Boon. A Bard Fey Beast Tamer might choose a Fey creature that acts like a familiar but turned up to 11 and has cool ways to boost it using Bardic Inspiration Dice.
ALso, a feat for improving summoning, and spells that specifically make summoned or controlled creatures stronger would be nice, and I'd go out of my way to ensure that they work well with familiars and ranger beast companions as well as any new archetypes.
Then I'd add in several level 6 or greater summoning spells that create a mighty effect that is summoning themed, like an angelic chorus that heals all allies and removes negative effects, and no damage can be dealt until the chorus leaves except to fiends and undead (which combines in fun ways with AoE spells if you're fighting such creatures, since you don't have to worry about friendly fire), or the new UA warlock's thing where they summon their patron's toothy maw into the fray.