No. An established business helps with the real-and-operating and non-marginal questions, but nationality, irrevocable commitment of funds, substantiality and the investor's ability to develop and direct still have to be shown on their own facts.
An operating company answers some questions and not others
Hypothetical example: the electricians assume that because the target has nine staff and steady revenue, the file is straightforward. Two problems remain. First, nationality applies to the enterprise as well as the individual: the business must be at least fifty per cent owned by nationals of the treaty country, so a structure that leaves the seller with a large minority stake and a controlling agreement needs examination.
Second, development and direction is about authority, not title. Set out who will sign contracts, hire and dismiss, set prices and control the bank account. Substantiality is proportional, judged against the total cost of buying or establishing this kind of enterprise, not against a fixed threshold.
And E-2 does not lead to permanent residence on its own, so a household planning to settle permanently should raise that at the start rather than after the purchase.