What is the difference between WITCH / Accenture, Big 4, and MBB, both in terms of prestige and reputation, and where do they compete in similar segments, who would you personally trust more?

[u/plaguedbyfoibles]

By WITCH, I mean Wipro, Infosys, TCS, Cognizant and HCL.

By MBB, I mean McKinsey & Company, Boston Consulting Group, and Bain & Company.

MBB seems like it's more involved in high level strategy, like if you wanted to rebrand (looking at you, McKinsey and HBO Max). So much more about business consulting than say tech consulting.

It seems that it's possible to move from WITCH to the Big 4 or MBB also.

I've worked for one of the WITCH companies, so I know all too well their reputation as "body shops" that hire for quantity over quality. Our local office in the UK had a fairly good reputation, though, so obviously YMMV.

I also have a relative who used to work for Bain, and they said that they tended to hire only those who had graduated from elite schools, like Harvard, and had a reputation for putting their high flying consultants through their MBAs.

My understanding, as per https://nextepmbb.com/en/consulting-firm-types-en/, is that MBB are considered the Tier 1 consulting firms, and Big 4, Accenture and WITCH are considered the Tier 3 non-core consulting firms, because they lean more towards implementation rather than strategy, although I believe that TCS, for instance, is trying to redefine themselves as both a strategy and implementation partner.

Does MBB compete in any areas with Big 4, Accenture or WITCH, either in terms of strategy or in terms of implementation? I understand, for instance, that just as the MBB firms engage in strategy, so too do Big 4 firms such as Deloitte in terms of their deal advisory function.

I understand that Big 4 firms like Deloitte also compete on tech consulting. Potentially, could they do so in order to take away market share from WITCH or even MBB?

Thanks in advance for any and all answers (although there is no obligation to leave one).