Casting first in defence + endgame spells

[Valerius]

Micah already said most of what I wanted to say but I'll add that I don't think the counter to these spells is to give attacking armies a free pass (a chance to buff before the defender's spells take effect) but to use a different force to attack (in fact, I'd say these spells are the counter to large armies/squads of mages and are working as intended). The decision of whether to attack and with what forces is just as much a part of the strategy as unit placement and scripting. Just as a solo SC may be met with an SC-killing squad so might an army be met with these spells. I don't see any reason why they should be guaranteed a chance to buff. It's like saying you have one tool and you want apply it to all situations as opposed to using something better suited to the job.

It is also worth noting that the changes you propose would have different effects on the direct damage spells vs. the MR resist spells. I think army of gold will reduce the effectiveness of rain of stones or earthquake to a greater degree than antimagic will the death/astral spells, especially since you can increase your penetration through boosters or adding mages to the communion. As Micah noted the net result might be to make astral nations even more powerful.