A production is only as productive as the people that make it up.
Manga production happens at a much smaller scale compared to anime production.
For anime production, on top of publisher front costs, you have to get your staff, sponsors, script, character/set designers, broadcasting rights, and advertising ready before the production even starts.
Typically only half the budget allocated to an anime is used by the studio in charge.
Manga production can vary greatly. Some authors are interested in creative input from their assistants, while others only ask them to assist. Some artists like do to as much of the work themselves as possible, others have their assistants fill in most of the page while the artist only draws the "name" (a kind of storyboard for manga) and main characters.
Anime are usually created and broadcast at a loss while profits are made from DVD/Blu-ray and merchandising sales. Most mangas are produced at a loss, their viability access by their rank in their parent magazine's reader survey polls and takubon (volume) sales.
Generally, it takes around 8,000,000 to 10,000,000 yen to make a "30 minute" episode anime, while it takes only about 2,000,000 yen to produce a weekly serialization, because it typically takes 2 months for a tankoubon can be compiled, at a 100-page monthly production rate.
On top of that you have to factor in rent for the studio, and payroll (pay + pensions) for that staff which typically is composed of 1 chief-assistant + 2 or 3 assistants + 1 background artist, typically a group of 4 to 5 people. Different authors/artist get different rates depending on the publisher and the experience/fame of the author/artist.
Most animators are contract employees to a production studio. Therefore they do not get benefits, pensions, or vacations. Because many productions employ so many animators for their tween animations it can be hard to keeps track of who's who and doing what.
A well managed small anime production can sometimes be more efficient than a large high budget manga serialization, but the opposite can be true as well. It usually comes down to who is an change and how the work trickles down.