Not true in my experience, but I only play with one other person.
We've both had these items, etc, in some cases more than once. My wife totally loves the Flail, but I've never felt that our games were lopsided when she had it. (she always buys one, btw).
Likewise, she whined, at first when I had the Scribe and the follower who generated spells, and I think a book that gave spells and I cycled like a madman. But I didn't win that game.
Maybe we're not as competitive as you all. We play for fun, certainly and we like to win, but our games don't always have huge imbalance because of these items.
I'm really hoping that the next time I get the scribe, and book/pet/follower that gives spells, that I also get
The Dungeon's Totem Staff. Maybe then I would think I was overwhelming.