I can see how compared to RS gold current levels these seem like huge nerfs but the underlying problem is that turm/ovl is too powerful currently and has been left at that level for too long.
It seems to me that once the cb update launches , summoning won't be more effective than herblore but after the summoning rework it's likely to become better.
In the absence of anything else I'd suggest using the xp on summoning since summoning gets more from the bonus xp since you'll save money and time in collecting charms. Do you remember how summoning was always an 1.1x multiplier on weekend bonuses, which was different from other skills , so as to not to be unbalanced? Now, it's just like any other skill, and I'd be buy OSRS gold able to take advantage of it if I had to summon extra xp.