There are 6 family members, introduced into service in the order of the pics below, I find them useful for padding out an armoured force because they're so cheap, but even though they pack a powerful punch, their open tops and thin armour mean they and their crews are very vulnerable to AT-rifles, light mortars, light guns etc, and even small-arms can rattle the crew, so I tend to use them from stealthy ambush positions rather than pushing them too far forward into the thick of things. Some had the excellent 76.2 mm gun, some had the even more excellent 75mm gun.
Some also had an MG, some didn't.
There's an increased chance of having tungsten as the war went on.
Speeds ranged from 22mph to 26mph except for the II (early) which flew along at 34mph.
Below is the order they were introduced into service.
They all served til the end of the war except the II (early) which was withdrawn in April 44.
Gun comparisons, the 75mm is best.
April 42
MARDER II (early)
April 42
MARDER III (early)
Jun 42
MARDER II
Nov 42
MARDER III
May 43
MARDER III (late)
Normandy