What are some potential dangers of decentralization in fragile societies?

I'm working on a paper where I consider a decentralized*/federalized* political system in Afghanistan. While there are many journal articles (a quick google search would show this) arguing in favor of a decentralized system, very few actually consider the potential drawbacks - and dangers - of decentralization in fragile contexts. This can be especially true in multi-ethnic warlord-dominated societies, such as Afghanistan, where a decentralized system could pave the way for a disastrous "takeover" scenario by violent non-state actors. Similarly, the potential disadvantages of having a complicated decentralized system in a region where the neighboring countries are hostile, and might take advantage of a premature decentralized system, are rarely discussed as well.

So my questions are for those who might have some experience about this topic.

• What are the potential drawbacks and dangers of decentralization in
  fragile countries?

• How much literature do we have that focuses on this?

• Conversely, is there any literature that argues for a centralized
  system in a fragile context?

Some relevant sample articles:

https://www.tandfonline.com/doi/full/10.1080/23802014.2016.1297207

https://www.jstor.org/stable/10.2307/26803230.

*I'm not using any specific definition or form of decentralization yet, so that is why I'm using it interchangeably with federalization