"overly rely" is correct and usable in written English.
You can use it when you want to emphasize that someone, or something, is depending too much on something else. For example: The company had overly relied on a single customer for much of its revenue, and when that customer left they were left in a difficult financial situation.
The American military official did not go into details, but said only that "we overly rely around here on linguists," the military term for interpreters and translators.
The concern is that we don't tend to overly rely on the P.E.B. tool so that rather than facilitating agreement it makes it harder for the parties to reach agreement.
Spotify, meanwhile, has begun to overly rely on the power of its popular curated playlists – like Rap Caviar – to cement its importance in the world of music.
In the light of urban planning and development perspectives, this study can become a lesson for other cities, especially in developing countries, which some of them may overly rely on natural resources-based economy, to anticipate the transition period after an economic boom due to natural resource endowment and its price decrease.
Too often, employers overly rely on salaries and bonuses to show their appreciation for employees.
We need to "be everywhere" these days but not overly rely on any one site or place.
The report concluded that the allies struggled to share crucial target information, lacked specialized planners and analysts, and overly relied on the United States for reconnaissance and refueling aircraft.
But Miles questioned the metrics used at Guantánamo for determining that threshold, saying they overly relied on body weight, to the exclusion of iron levels, calcium levels and red blood cell size, which he testified provide more precise measurements of malnutrition-related dangers.
She said investigating officers had "overly relied on people perceived as professionals and experts in their field" at the hospital, for information.
Leetaru is even more wary of overly relying on social media to make predictions, arguing that in many cases even seemingly public events, like protests, have a hidden side to them.
It's surprisingly short, lacks imagination, and overly relies on gimmicks that prove more annoying than surprising.
