Valid points, but still if you clear out a few of the troops / towers at the chokepoint itself before teleporting/flying ahead across the whole base, a sizeable army + reinforcements could easily hold off the hostile waves and even progress forward a bit.
Meanwhile, don’t forget surprising mummies: Each dying mummy releases a dozen of (potentially boosted) knights, and those will obliterate the gate or anything else they can reach. So beating a gate with only mummies is very well possible. And in fact, for high lvl gameplay, that is what you will do most of the time anyways, maybe with the odd raging wolf in between if you managed to get some through the base alive, or just without any other support.
Now, sure not everyone has boosted mummies, but still more than there are with doom gate. And without doom gate, even spells are enough to bring down the gate, if you have a little meat shield (which unboosted mummies are; not to mention their stunning spell).
So, ofc no single spell guarantees a win, but this scroll would be a very very close to sure way for killing the gate for anyone with at least mediocre raiding skills (given one doesn’t decide to just attack someone with 3k trophies more than oneself^^).
So this scroll would have a huge potential for trophy stripping and stuff…
Nonetheless, of course, killing the gate with most defenses untouched, might not give you 100%, but only 80-90%. Anyone remembering the gate-killer designs that were made impossible with version 1.8 knows that even a 90% success can be something quite unsatisfying if you’re trying to beat it all, but still that suggested scroll would remain very powerful.