Here's an excellent video of a stugna crew in action.More or less a classic 2nd gen ATGM. They are cheap to produce and easier to develop than, say, a Javelin, Spike, or MMP.
It really doesn't take much in the way of warhead design or defeat mechanism design, to defeat a Soviet tank. So a simple ATGM like that can be effective.
Would it be of any worth to other European nations though? Not at all.