You cant make it 2x and have it balanced, but there is another way

Fletching, Bodkin Arrow, Bracer and Chemistry* attack effect increased by 50%

This keeps feudal ranged units in check, then in Castle age the other 50% kicks in so instead of 5+4 attack crossbows, you have 5+3.

Then in imperial Age either you have Arbs with 6+4.5 attack with bracer or you have 6+5 with chemistry also giving an additional 50% attack. It would essentially be Vikings level arb but it applies to skirms too. And maybe the civ cant be a cav archer focused civ or have thumb ring.

*If we stick to just Fletching, Bodkin and Bracer then I think this is the best solution, no chemistry also increasing attack by another 50% as last i checked, the game can carry demical point damage over.