Google is moving towards a more topic-centered approach when returning results. This is apparent when we get monthly search volume data from Google. Keywords “seo” and “search engine optimization” both give the same 135,000 monthly searches.
Since Google's "Panda" update, Google is now looking for LSI Keywords to clue itself in on what the topic of your web page may be about. LSI Keywords (latent semantic indexing) are simply other keywords that are related to a certain topic. So if you are writing a blog article on “How to unclog a toilet without a plunger”, your blog will naturally contain words related to “toilet” and “plunger” like “bathroom”, “restroom”, “clog”, “bowl”, “sewage”, “water”, etc.
It never hurts to use tools that helps you make sure you include as many related LSI keywords as you can (naturally of course).
My company is building the first AI-powered keyword research tool which includes an LSI Graph where you can easily see related words.
If interested, you can check it out here: https://www.twinword.com/ideas/graph/
I would recommend you to check the Moz Guide https://moz.com/beginners-guide-to-seo
Maybe you're hitting some ranking factors but not the most important. First you need to define what type of SEO you're trying to do. Local or National? National takes more time and you have more competition (I know you're nitched)
Choose one keyword per page and make sure is included in your Title, H1, content and URL (Except the Home page). Make sure you have only 1 H1 and you follow the heading structure.
Optimize for the user and not for the search engine :)
Another thing to keep in mind is site speed (Check https://developers.google.com/speed/pagespeed/insights/?url=http%3A%2F%2Fwww.actisspartners.com%2F&tab=mobile) It seems you need some help on your website speed.
Good Luck :)