A megacity is defined as a very large urban area, usually a metro area consisting of a main city supported by several satellite cities. A megacity is characterized by having a big population that continues to quickly grow due to urbanization from other regions, with relatively noticeable pockets of poverty due to wealth gap.
Le Corbusier's concept of urban planning envisions polished infrastructures (wide roads, clear sidewalks, spacious public facilities, etc.) within cities with well-defined sectors (e.g. clear separation of residential and commercial areas, etc.) This concept desires a city that looks good in an aerial view. Examples for this concept is the recent form of Thamrin/Sudirman in Jakarta, downtown Singapore, etc.
The informally-called "chaotic warm" approach is the opposite: a city that looks “messy” from up above but feels "warm" to its inhabitants: for example, the experience of urban villages, city alleyways scattered with street food hawkers and hole-in-the-wall establishments. Examples to this would be Brooklyn in NYC, Hong Kong’s art district, Kota Tua, etc.
For the purpose of this debate, both approaches would also aim for cleanliness, relative order, and security, albeit in different ways of delivering/implementing them.