The Necropolis can come not only for the Conflux but also for any other Castle. At the Conflux, the mages already have 3/3 stats from the start, which is not the case for any other Castle (2/3 or 3/2 is the highest for others). They can also use their spells to attack more powerfully and in a more overpowered way than with other Castles (and considering that one of the elements is already available from the start, reducing the spell cost and increasing the damage). As for battles only with butterflies, someone is getting carried away here... And what about the army from the third hero, does it not exist? In general, restrictions were specifically introduced for the Conflux so that it wouldn't be as overpowered at the beginning as it is from the second week, with its overpowered bird growth and elementals with mass damage, as well as the strongest tier 2 ranged units in the game. And all this is still with the magical support of the most powerful mages in the game in terms of skills (and the tower is built immediately). You can also recruit Storms and fight with them (or, if you want, you can also create butterflies and crush everything on the first map without upgrading air units, since there are few of them – in this case, you need to choose one or the other... (although if you have a good start with air units or their support, then you can kill everyone on the first map even better than with other Castles, even without upgrading them)