Ds had 2 teachers a few times and it only ever worked well for French where you need to be practicing all the skills throughout the course, they taught the same topics at the same time with one teacher focus on reading /writing and the other on listening/talking.
Other subjects such as chemistry and maths they split the course between the two teachers (I assume easier for teachers to plan), but it put more pressure on ds as he was always learning two topics at once.
One class got chemistry unit 1, time to revise, end of unit 1 test, unit 2, time to revise, end of unit 2 test, time to revise before prelims. His class got a mix up of unit 1/2, everything running late, they were still getting new content the week before the tests and then they got both end of unit tests in the same week, just a week before prelims so no time for feedback before. Both teachers constantly let the class know they were not happy with the way they had to teach, he knew from the other class they were miles behind, all of which did wonders for his motivation. He scrapped an A but it completely turned him off chemistry which was previously his favourite science.
In English they had two teachers with completely different ideas on how to structure answers and it left them confused.
From ds's experience we strongly believe the continuity of one teacher is much better, but there isn't anything you can do about getting 2 teachers other than prepare your dc and ensure they stay organised and on top of the work. 3 teachers is ridiculous.