Ideas and suggestions.

2Qwertyy - of course, without Earth and Air, it's impossible to play large maps, and even with your changes, Water clearly won't become a skill that a hero will take on them. But besides HL maps and Jebus maps, there's also M200, where Water has a right to exist. In fact, everything has a right to exist there. Let's move on to mysticism and, most importantly, the artifacts that symbolize this skill. All three artifacts +1+2+3 mana = treasure. It would be logical to also change their classes - treasure, minor, major. The collection of them would still remain a relic. Regarding property artifacts, you can also change the classes of the artifacts: change the purse to minor, and lower the bag to major.