No local SEO marketing consultant can guarantee you a #1 rank position with the search engines, and if any ever does, do not work with them.
Ranking within search engines is a competition of sort between your website and other websites. Achieving a high ranking is like the old joke about the two hikers and the hungry bear. To live, a hiker does not need to outrun the bear, he needs to outrun the other hiker.
No local SEO marketing service can control what any 3rd party does. The search engines are a 3rd party we can not control, but equally and perhaps more important, your competitors are 3rd parties we can not control.
Now technically you can guarantee to outrank anyone, by publishing more content, of higher quality, more often, and for longer.
So if you absolutely feel you MUST outrank Starbucks for the word Coffee, you could from a technical perspective. However the effort to do so is simply not worth it.
What matters to your lead generation efforts are unique visitors, visitors from organic search, and page views.
Monitor those, track those, covet those, work to increase those, and add to that an effective conversion strategy, and your business will generate leads through your efforts.SEO Needs Link Building