Citation Question for multitrade service companies

If I am an established electrical contracting company for decades with the same address and I add plumbing to the mix possibly, will it muddle everything up citation-wise? The last twenty years these triple threat MASTER trade companies seem to be popping up here and there. Everyone has a Plumbing, Electric, & Air company.

In hindsight, if one had a new company with all three call it x service company? My citations are already fractured between the old INC and the new LLC and just my dad's name as a person. Somehow my G+ listing had me down not as a sparky but an electric machine repair guy which only took two years to change.

For instance the company is known as Electric Company, so if it sees a plumbing citation, will that break the internet for categorization? I heard G+ subtracted multicategories a while back. Do I file a DBA or does that do any good really? Is this a problem for other contractors that have three trades? Roofing, Siding, Gutters?

Do I just place that aspect of the business at another address and build clean from there in the plumbing and heating category?

I would also venture to guess since my website has electric in it, to just keep it focused on electricity and do the same for the other topics instead of being an event horizon of multi trade? Maybe a link off to the other site?

Would any of this really make any difference in local?

A lot of questions but really you won't have any issues citation wise as long as you're using the same NAP consistently.

The thing with Google Places is you can have up to 5 categories but I reckon you can really only focus on a couple trades with any effectiveness. I have ranked for Roofing and Siding locally before but you might have more difficulty ranking for more business types because Google only has so many categories and I imagine they'll only categorize you in a few certain places max. They're not going to let the same business dominate a ton of different types of businesses locally, there's got to be some kind of cap somewhere.

I think a lot can be said about targeting a certain niche specifically. You might feel threatened by those 3 trade companies but in reality when someone wants an electrician chances are they're going to call someone who specializes in that field (as long as you're on front page when they search).