Croatia is in the Group C, rather. Group C is basically everything behind the "iron curtain" + Greece/Turkey.
Eventing will have its technical XC level reduced from 4* to 3*, so it should be somewhat easier to get around, while the time will have its influence of course. Olympic format - 4* dressage, 3* XC, 4* jumping - will be used at WEG for the first time (with 4-member teams though), however WEG should still give some insight.
European championships have always been on 3* level for example, so it's not getting terribly easier either.