Can an SEO company fix over-optimization issues?

Yes, and the fix is mostly rewriting and consolidating rather than adding anything new. Over-optimization means pushing keywords and links past the point where they help a reader, until the page starts to look like an attempt to manipulate search results. In practice it shows up in four forms: keywords crammed into page text, keywords forced into the anchor text of your own links, near-identical pages made for small variations of a search, and links from other sites built with keyword-rich anchor text. Google describes each of these in its own documentation, so a company should be able to show you which description a page matches before it changes anything.

Keywords crammed into the page

Google’s spam policies define keyword stuffing as “the practice of filling a web page with keywords or numbers in an attempt to manipulate rankings in Google Search results.” The examples they give include “Blocks of text that list cities and regions that a web page is trying to rank for” and “Repeating the same words or phrases so often that it sounds unnatural.” The first example is worth checking on any local business site, where lists of every town served are easy to add to a footer or a service page.

The fix is a rewrite for the reader: the page covers its subject in plain language, uses the terms a reader would expect, and drops repetition and lists that exist only for search engines.

Keywords forced into your own links

Descriptive anchor text is not the problem. Google’s guidance on links says: “Good anchor text is descriptive, reasonably concise, and relevant to the page that it’s on and to the page it links to.” The problem is forcing it. The same page advises: “Write as naturally as possible, and resist the urge to cram every keyword that’s related to the page that you’re linking to (remember, keyword stuffing is a violation of our spam policies).” And it gives a simple test: “Ask yourself, does the reader need these keywords to understand the next page?”

A company reviewing your internal links should apply that test link by link and rewrite anchors that fail it, rather than stripping descriptive words out of every link.

Near-identical pages

Sets of pages that differ only by a word or a place name are the third form. The spam policies list, as an example of doorway abuse, “Creating substantially similar pages that are closer to search results than a clearly defined, browseable hierarchy.” The fix is consolidation: the company decides which pages serve a distinct purpose, merges or redirects the rest, and rebuilds the remaining pages so that each carries content of its own.

Links from other sites

Links built elsewhere with keyword-rich anchors are the hardest to fix, because they sit on sites you do not control. The company stops any such link building, asks for removal where it can, and applies Google’s test for disavowing links only if that test is met. That decision has its own conditions, and a company should be able to explain them for your site before it touches a disavow file.

How the diagnosis should work

Diagnosis is reading, not a score. The company reads the affected pages, lists your internal anchors, reviews the anchors of links pointing to your site, and checks the Manual actions report in Search Console. You may hear target percentages for different anchor types; the Google documents cited here describe the practices without setting any ratio, so a percentage is a company’s rule of thumb and should be presented as one.

What recovery looks like

If there is a manual action, the cleanup has to be complete before a reconsideration request is filed, and the result is Google’s decision. If there is none, the rewritten and consolidated pages are reassessed as Google recrawls them, and no company can promise when or by how much rankings will change. What it can show you is the list of pages rewritten, merged, and redirected, and the reasoning for each.