I sold Huawei Storage for a while and my experience was as follows:
1: Forget most US owned Enterprises, they will simply not allow a Chinese product anywhere near them, and to get anything like a top 3 spot, Huawei will need to sell into the US where they are banned from supplying Telecoms providers. That's going to be a big ask.
2: If a company has a budget for $1m they can afford a Tier 1 vendor. It's the old " you don't get fired for buying IBM" scenario.
3: For Huawei (or indeed any challenger to the big incumbents), to persuade customers away from buying what they know and trust, there needs to be a competitive advantage, i.e price.
Unfortunately, in my experience, Huawei simply isn't cheap enough. The perception is that Chinese = cheap and Huawei is typically 25-30% cheaper than a tier 1. The need to be more like 50%.
4: If a company is persuaded away from buying a Storage product from a tier 1, there are other options they will probably look at first. In Networking, my experience was that a prospect persuaded to look away from Cisco would then turn to Brocade, F10 or Arista before thinking about Huawei.
5: Huawei support used to be distinctly lacking. Unless they've changed, they need to seriously sharpen up their act because the attitude is too much "sell and forget".
This isn't the first time Huawei have made such bold proclamations of market share, but the fact is that these claims are usually made by big-hitting Chinese managers who have come out of their Telecoms business where Huawei is a top 3 player and they think they can achieve the same in other product areas, and they make these claims because Huawei senior management expect them to make them!