Its the same thing as initiative, only worse, initiative no matter how low it is your units will attack based on position(piston 1 first, then 2 so on and so forth), if ur initiative is lower than your opponents then there position 1 will attack then urs, no matter how much more they have. Speed takes that whole concept and throws it out the window. Speed is (obviously) how fast you are, If someone lowers your speed itll no longer go in order of position but in order of speed. so its possible ur opponents whole team will attack before you do. sometimes if it only a few of your units have a lower speed then its possible for your position 4 unit (or any other unit) to make an attack before any other unit before.