They're a good bit bigger than the S5 template, from memory they're somewhere around 52-55mm tall depending on how you measure them, but the main issue is the GI Joe sized sniper rifle, which sticks out 10-15mm past the base edge.
Here's a decent side by side with a fairly normal S2 miniature they're like 1.5X the height and 3-4X the area but yeas as Caz said the biggest issue is sniper bro sticks out nearly as far as he is tall from the base due to his weapon.