Break Twister

IR35 seems to be cast very widely. I would be grateful if HMRC could consider and respond to the below examples. Most solicitors firms are owned by less than 20 partners thus meeting the "director or partner who owns or controls more than 5% of the company" criteria for a PSC. As such, any medium/large company (over £10m or 50 employees) instructing a solicitors firm would need to carry out an IR35 assessment. This seems ridiculous but that is what the law states. Can HMRC comment on this please? Furthermore, Barristers typically operate via a Ltd company and are thus operating within a PSC, an "employment intermediary" according to the IR35 legislation. Another common occurance is a Barrister who only works for a single solicitors firm. In this example should the solicitors firm carry out an IR35 assessment on the Barrsiter? Is the Barrister likely to be caught inside IR35? If not, why not?