Balance ranged units by buffing siege?

Ranged units, particularly the crossbowman, have more and more become the dominant meta over the past few years, to the extent that some pro players claim skirms (skirms!) are the best unit in the game simply because they hard counter ranged units.

There are a few ways to shift the meta besides direct nerfing, one of which is buffing the counter. Rather than buffing skirms, which are already good and not every civ wants to go for (notably Burmese and Turks), how about we buff the gold counter, which is siege?

Here are several ideas, thinking particularly about scorps and mangos in Castle Age:

• Increase siege tankiness. Probably buff their HP by +10-15 points to make them harder to snipe. Cav will still take them down really fast, but it will take a significantly bigger ball of xbows to two or three-shot a mangonel. Bonus damage vs siege can be increased so a mango still one-shots a mango, if that is still desired (which I'm not sure it is).
• Rework siege engineers. Make it cheaper and available in Castle Age, or have two tiers where only the imp tech increases (bonus) damage. Also allows more civilization differentiation for siege units.
• Decrease training time. Siege units often function as just-in-time defense versus a power spike ball of xbows breaking into your base. Making siege train faster would make them better at this. It is also historically justifiable, since siege units were built quickly if expensively, whereas good soldiers might take months or years to train.
• Decrease cost. It's less of a gamble to go for that mangonel in defense if it doesn't cost a whopping 300 resources.

Let me know what you think. I'm not necessarily advocating for this, just food for thought that I want other perspectives on how it might change the game (good or bad).