These roles definitely can break out fine in a flat structure - Shadowcat is a relatively small organisation so we don't so much have seniority as "person X has tie-breaking power in the absence of a consensus in area Y", where if Y is a particular project person X is usually the primary developer rather than anybody with a significant management focus.

I'm the technical founder and tend to focus on the 'lead' role, our business founder focuses on the 'director' role, and we used to split the 'lead of leads' part between us but have now acquired a general manager who does that - as well as being the resident entropy crusher (I can only keep state mentally, he keeps state on paper/in files - ergo he both scales way better than I would and acts as an excellent L2 cache for the state I need :).

Of course, it's not quite that simple - I still want to have a decent level of involvement in the overall direction of the company, but so far I've found the "take a weekend to build a proof of concept of something nobody else realised could work" approach quite sufficient to keep my ideas in play.

Note that we're well under 20 people and don't tend to grow that quickly, so I can't speak to how this will scale in the long run - but given the bigcorp style of the post's examples I thought it might be of interest to people how this maps onto a small organisation.

-- mst