In doing so, don't you fall in trap of ending doing everything by yourself. The solution in your brain is now ready for everyone to see and work with. Doesn't this in a way cut down their (other designers in the team) natural process of aligning their thoughts with yours. Now they can simply work with what you've provided because if a solution is given by design manager, it must be the best.

I do not wish to counter your opinion here but I feel 'how-about-this' is also not the ideal solution to the stated problem.