care to elaborate? just curious
If you try to flank on maps like lazur you most likely to not only achieve nothing thanks to blob smashing you lone squads to dust, but even die on retreat thanks to extremely bad retreat paths. And even if you manage to get out, you will retreat all the way back to base which puts you in disadvantage of squad count for next minute.
Ironically, only faction suited for flanking in 3s/4s is OKW, they are not punished for retreats like all other factions, can choice retreat paths with med hq, more they fight more of their amazing vet they gain and if they manage to steal support weapons, it almost gg.
Also, using green cover leads to bunching and easy squad wipes from mortars (for both sides).
Thats first things which come to mind.