Not sure why this is downvoted. All the big four and smaller firms have tax advisory departments which advice on how to avoid (not evade) taxes. They sometimes set up the structure as well but usually that's done by a third party, following the tax advice memos from firms like Deloitte.

It's hardly secretive, many (academic) books have been written about it. You can find a million fiscal books and papers on fiscal literature and many top firms offer tax avoidance advisory services.

Tax evasion is different, it's entirely baded on being secretive due to its illegal nature. But that's not what the article is about.

Thats a fairly big call, but highly likely to be accurate

Not a big call, it's what they do. They have huge departments for (legally) optimizing your tax.

Source: I used them to do this for a firm I was working for.