Which is exactly why you need to constantly modify your plan as needed, anyway. Again, the best-laid plan won't survive contact with the enemy, but that's no excuse for not having one. Your focus is on some intrinsic flaw in the queue. You should focus on poor design catering to dumb people.
http://www.gamershell.com/download_505.shtml
Try this game. It's a wargame, but the same point remains. RTwP. Try it on realistic command delays, meant to simulate the logistics of proper command & control. Depends on where your units are, it can take you a very long time for your orders to reach them, sometimes up to hours. The game implements chains of command, so you can give order to 'HQ' units, whom will determine a plan for all their subordinates based on your specifics (or, you can micro everyone if you want). Each time you send a new order, it takes some time for the AI to set up a new plan, representing the inefficiency of constant changes in orders. The way it works (again, if you put it on realistic delays - you can also choose to have no delays and play it 'RTS' mode) is that you need to thoroughly think out your grand plan and try to outthink the enemy, anticipating enemy moves, and act preemptively. Then you let your plan unfold. You need to prethink all your moves, giving orders hours in advance in anticipation of what the enemy will do.
You can spend a lot of time trying to get a hold of the big picture instead of micromanaging individual units. THAT's what strategy and tactics are all about for me, not playing a twitchfest and dancing single units around as in most conventional RTS. I want to win because I outthink the enemy, not because I click faster or I memorized more building patterns.