If I could tell you plainly what specific forms of hierarchy are and are not acceptable, a consistent and coherent ruleset that 100% accurately defines that, I'd have essentially created a grand unified theory of anarchism.

I am not that smart.

I would argue that part of the entire idea of anarchism is that no one is, that people and groups will always have differences, even if they broadly agree on general principles.

Generally speaking, I would say start with the idea of 'a system is to be judged by what it does or produces, not what it claims to do or produce.'

Apply that principle to everything, every social construct, every machine, every bias or norm, every political system, every monetary or financial system, every mode of production.

There will commonalities in many of these subsets, but many of them will also have unique elements thay require at least some level of specialized knowledge or serious study to well comprehend.

As to anarcho-syndicalism, well I mean wikipedia is a decent starting point ->

https://en.wikipedia.org/wiki/Anarcho-syndicalism

Anarcho-syndicalism is an anarchist organisational model that centres trade unions as a vehicle for class conflict. Drawing from the theory of libertarian socialism and the practice of syndicalism, anarcho-syndicalism sees trade unions as both a means to achieve immediate improvements to working conditions and to build towards a social revolution in the form of a general strike with the ultimate aim of abolishing the state and capitalism.

Anarcho-syndicalists consider trade unions to be the prefiguration of a post-capitalist society, and seek to use them in order to establish workers' control of production and distribution. An anti-political ideology, anarcho-syndicalism rejects political parties and participation in parliamentary politics, considering them to be a corrupting influence on the labour movement.

In order to achieve their material and economic goals, anarcho-syndicalists instead practice direct action in the form of strike actions, boycotts and sabotage. Anarcho-syndicalists also attempt to build solidarity among the working class in order to unite workers against the exploitation of labour and build workers' self-management.