why does the us army have much longer deployments than other US military branches?

Question

us army deployments are the longest at a minimum (nowadays) of at least nine months.

 The marine corps has seven months,  while the air force at most has six months (and I've even heard the air force has had deployments lasting just four months).

 I've heard back in the height of the Iraq/Afghanistan war,  army soldiers would deploy for 15-18 months, then come back and in another year, go back to Iraq/Afghanistan again for another 15-18 months.

  Why does the army have longer deployments compared to the other branches, and do you agree that the army should have shorter deployments in line with the other branches?

https://www.armytimes.com/news/your-army/2020/10/1...

Answer 1

The Army has the most personnel to do the longer deployments but these days they are lucky to do 1 deployment during an enlistment. While the Marines can do 2. Right now Navy deployments are 7-8 months plus and that doesn’t count all the work ups and exercises in the year so they can be the longest deployed. 

Answer 2

Nine months is not unheard of in the Navy either.  

Could be worse.. my grandfather was gone nearly three years with ZERO time at home the entire time.  At most he got a few days R&R locally( Atlantic Theater) during WW2.  

Answer 3

air force deployments are based on the aircraft and thier maintence cycle, air craft can only fly so many hours without needing major maintenace

are you willing to take a pay cut, to fund shorter army deployments?