Question about marketing related to non-Internet businesses

I've had a question come up recently, since I work for a new, small company that is currently paying to have a professional website put together, and while I'm the official go-between with the web designer/programmer, another person at the business with some clout has been quite persistent in wanting me to guide the web developer in certain directions based on his own opinions, while I think it's a better approach to leave them with their creative freedom as much as possible, since they have a very good track record.

Here's my question for your guys: the main disagreement is how to present our company as a whole. We started off in one market (contracting), and in just over 18 months of operation, we started planning a quick exit from that industry, because a combination of factors including incompetence and poor financial planning led us to lose roughly 1 million dollars in that period of time, more than half the initial investment. We had a very basic website, with no real design or function throughout this.

We are now starting in a new direction: commercial equipment rentals, with the same brand imagery, but a different company name, in hopes of being able to turn a profit. This has much more of a retail element, so I'm working with the web developer to set up an online presence and POS/eCommerce system that blows our will-be competitors out of the water.

Here's where I disagree with the other fellow at my company about both the web design, AND business approach.

By all internal business measures, we failed at the contracting venture. Some of our future rental customers may know our name because of the 18-month try at contracting, but we most certainly have not established our company as a household name, or anything of the sort. Most of our future customers in commercial rentals will never have heard of our brand. We plan at the moment to continue operating the contracting business to close out current contracts, and continue the temporarily available fraction of work that was a little bit profitable (less than 10% of the business).

He wants us to essentially present ourselves online as what I can only call a "conglomerate": one company that operates in multiple industries at the same time, like Yamaha (combustion motors and musical instruments) or Rolls-Royce (jet engines and luxury automobiles). I think these two operations should remain as separate as possible in the consumer's eye until they both are able to establish themselves independently, which currently neither have done.

I'm of the opinion that trying to create any sort of an online presence that links the two sides of our upcoming business operation is a very tacky way of making it look like we're a company that is trying to do too much, especially since we haven't established ourself in either industry yet. If I stumbled on a website that contained "Name I Haven't Heard of Hair Dye and Hedge Fund Management" I'd think they must be not very great at either, or they'd just be doing what they're good at. The odds that a business springs up with both those talents at the same time seem low. I also think that a conglomerate only really makes sense when two giants in different industries combine, or one well-established giant taking a first stab at a new market, like Microsoft getting into video game consoles, when they are a software development company.

The impression I get is that this other fellow at my company feels like we should be able to present ourselves as a one-stop-shop for whatever (he has dreams of also being a home developer, and brick siding manufacturer), and that will help our business succeed. As a side note, he also still thinks we should try to continue trying to build our operations in the contracting market, despite our still-fresh failure in that market. (He is one of two 50/50 business partners)

Am I out to lunch about my idea here? I keep trying to imagine myself in the customer's shoes, and I can't think of any scenario where I'd want to give my business to a company with a very limited and brief reputation that shows us already trying to do two totally different things, and having little success to speak for in either.

Is there an approach I'm not thinking of to bring this guy over to my side of the table? He has no business background whatsoever, but is very attached to is opinions on the subject, even when those with real training completely disagree with him.