I was impressed by @MuaaDip’s videos and decided to do a bit of testing myself. I’ve used two teams: one with all the 5 colors and one with 3 Purple and 2 Blue. I’ve only looked at the initial board, because it was easier to count the tiles. The results:
Average number of tiles for 31 boards where I attacked with 5-colors:
Average number of tiles for 19 boards where I attacked with 3 Purple and 2 Blue:
(I have fewer boards for the 2-color team because it’s not a good team and I’ve only used it when I didn’t care about winning the raid.)
While the sample size is too small to prove anything, the averages are close enough to NOT say “I’ve experienced fewer Purple & Blue tiles”.
Edit: in case “I’ve counted 50 boards” seems odd: I’ve wrote a program to count the tiles from screenshots. So, the counting was very accurate.