I love Banner, but it's set up to fail

I don't have a problem with Banner of Command being designed the way it is. If you're a heads up player, it's got some nice applications. But it's designed to fail, and I personally believe it needs some alteration.

> For the first 20 minutes, 1 Siege minion is spawned every three minion waves between the melee and caster minions. After 20 minutes, Siege minions spawn once every 2 waves and from the 35th minute onward, Siege minions spawn every wave to accelerate the game pace by making pushing easier.

My problem is that using Banner on anything except a Siege minion is almost a waste. Unless you've managed to put one together before the 20 min mark, in which case hitting the first wave might make sense. Conversely, as the game goes on, Banner loses it's importance. Those initial towers are Banner's great benefit. Absorbing multiple hits beyond what is reasonable from a siege minion.

In the late game, the biggest benefit is a well timed Promo on a siege minion to push out the lane. But people want wave clear cash, and that attracts the enemy, who typically makes short work of the Promo. There are obviously multiple solutions to this problem, but all changes comes with problems. Whatever the suggestion things need to change because as of now it's set up in the worst possible situation.

If I'm obligated to offer a solution, then my thought would be that Banner no longer affects a minion, it affects an inhibitor. In this case, the next time that inhibitor produces a siege minion (or one passes it, since that isn't exactly how it works), it will generate as a Promoted Minion. This would have two changes of real significance -

1. Timing. It would mean that you no longer have to be in the base at the right time, and can send a siege minion with perfect timing. Having said that, it means less control. Unless you're monitoring which wave came when, the ability to land a perfectly timed Siege Promo has been decreased. Just the same, this "counting" strategy is another lane of planning that doesn't enhance a persons odds greatly, but does give some benefit to those who get practiced at the art.

2. Cooldown on Banner. It would in practice make this much shorter. When casted on an Inhib, it starts its CD then, even if it doesn't have a siege minion on the field. The end result could be that sieges get bottle necked prior to 20 mins. Again, this could produce powerful benefits, but it does not seem likely unless you're expanding significant time on landing that outcome.

Anyway, thanks for reading and I look forward to any discussion.