Both 1 & 2 are valid strategies for underdog consultancies. Consultancies that are very good at #2 may also have better ability to keep people, who are exceptionally good at some specific tech or domain, because they usually have higher rates and peers that are good at the same thing.
As for product-minded engineers, there is often more freedom at a smaller a consultancy than in (many) product companies. You can switch projects every 3-18 months, select a new technology you want to learn, have big ownership on the helping the customer building the product, etc. To some people this is ofc a downside and a lot depends on the kind of client/project you're working in. Much of this also is lost, when the consultancy starts taking on bigger projects with bigger clients that already have much of these things set in stone.
As for product-minded engineers, there is often more freedom at a smaller a consultancy than in (many) product companies. You can switch projects every 3-18 months, select a new technology you want to learn, have big ownership on the helping the customer building the product, etc. To some people this is ofc a downside and a lot depends on the kind of client/project you're working in. Much of this also is lost, when the consultancy starts taking on bigger projects with bigger clients that already have much of these things set in stone.