If your head count is 5 or less, one brillian jerk (BJ) can carry the team on his shoulders. If BJ's a 10x programmer, and the other option is to hire a brillian and nice (BN) who's merelly an 8x programmer, you are better off with the BJ as tech lead. Assume your core team was 5x, 4x and 2x before the hiring of the tech lead. The 4x and 2x guys will probably slow down BN to 6x, so you end up with 17x of team throughput. BJ, on the other hand will make 2x quit out of frustration, and 4x will be demoted to 2x because he will struggle to cope. 5x, on the other hand, is pushed beyond his zone of comfort and raises to 6x. Now you have a team throughput of 18x, but you will be paying one less (junior) salary.
That extra throughput is also better spent because instead of 4 people discussing how to do things, there's 1 jerk bossing around 2 non-jerks. Cancel all team meetings!!!
Now, make the team size 15. Most of those will be 3x and 2x programmers as well. Seeded with a 5x, two 4x and the village idiot (VI, whom we will peg at 0.5x, just for the Lulz). So, the BJ has the VI kicked out, starts making much neglected changes, and everything seems to be going in the right direction. But then, your rank and file get demoted -1x because they also cannot cope with BJ's rapid changes. BJ might be seen as keeping the boat afloat, but in reality his productivity is neglected by everybody else's fuckups (which are BJ fault, because he cannot be bothered to let the team know what he's doing). 5x and one of the 4xs quit in disgust of the general chaos, and 6 months later, they are back with a competing product and poaching the big team clients.
So, it does not sound as if BJ "delivers" as much as you thought, does it?