The phrase "assistants started" is correct and usable in written English.
It can be used to indicate that assistants began a particular action or task.
Example: "The assistants started organizing the files as soon as they arrived at the office."
Alternatives: "assistants commenced" or "assistants began".
Four years ago, she and her assistants started systematically photographing records held by the French Foreign Ministry.
About an hour into the wait, some assistants started making popcorn in a movie-theatre popcorn machine — something that I would later learn signalled Lorne's imminent arrival.
After a spry set from the legendary Buddy Guy, various assistants started rearranging the crowd in order to create just the right blend of sex, youth, and spontaneity.
[Excerpt] In 2013, a naked hard drive from Fiji arriving in my small religious archives (an equivalent full-time staff of 2.5 – one archivist and two archives' assistants) started me off on the path of digital preservation and, in particular, the digital forensics practices that are beneficial for archivists.
The community health assistants started conducting regular house-to-house visits creating awareness on chronic conditions in general and for diabetes and hypertension in particular.
I also get REALLY irritated when sales assistants start asking you a million questions about what you want.
So when Christen Press, shooting fifth for the U.S., drove her shot well over the crossbar, Sundhage and her assistants starting celebrating.
One assistant started work at 9 a.m. and quit at 2 p.m. after witnessing an outburst.
But when I tried a different, larger Boots to buy an item I had forgotten there were no signs and the assistant started to put my card into the chip-and-pin machine before I mentioned contactless.
A part-time project assistant started working with us in March of this year, which has enabled us to offer flexible meeting times with student organization leaders outside of the traditional 9 to 5.
One day we sat down, and the field assistant started clicking his fingers to get our attention and pointing at the ground.
