According to "Stora Nordiska Kriget 1700-1721" by Höglund/Sallnäs there were four units with Saxon soldiers:
Sachiska infanteriregementet 1152 men(Schommer), formed in 1707 with Saxon POWs. Disbanded 1721
Sachisk infanteribataljon(Straelborn) 510 men, formed 1707 but capitulated to the Danes in 1710
Sachisk infanteribataljon(Boije) 521 men, formed 1707 and destroyed at Kolkanpää 1708
Sachisk infanteribataljon(Seulenburg) 518 men, formed 1707 and destroyed at Kolkanpää 1708
All dressed in blue uniforms with yellow turnbacks and stockings. The first two in blue karpus and the other two in black hats.
There were many other enlisted units with soldiers from the Baltic states, German, Swiss, French. Most dressed in Swedish uniforms but a few in captured uniforms or civilian dress