Tech switching into champions to counter Halb+(Siege) Onager: Is it Legit?!

In response to several recent posts I wanna dig deeper into the struggle some civs experience against (siege)Onager+halb compositions.

I brought forward the problem of the incas which have trouble dealing with onagers that are protected by champions or other strong infantery units, since the only mobile unit (Eagle Warrior) gets melted by champions and adding their own siege can be expensive.

I also read how chinese have trouble dealing with Onager+halbs, because of their weak cavalry - which is countered by the halbs - and their lack of ranged siege (no bbc, no Siege Engineers)

both these civs have a similar army composition of slow archers (chuks and slingers) and siege rams, and their quick units being either too weak, or too costly to trade against enemy halbs.

I guess the following civs all would experience the same problem, due to lack of good ranged siege (no BBC, no SE, no Siege onager) and weak or very costly mobile units to take down halbs+onagers (unupgraded scout line, anything <paladin or not fully upgraded cav, no quick infantery units)

• incas
• chinese
• mayans
• vikings (they do have Siege Engineers and berserks would do well)
• japanese (they do have Siege engineers and samurai is a good option)
• italians (they do have BBC)
• Byzantines (they do have BBC)
• goths (they do have BBC)

(any civs I forgot?)

Now someone mentioned it is possible for many of these civs to switch into the swordman line (champion), which would counter the halbs and potentially swarm enemy (siege) onagers. I have seen enough big badabooms to realise onagers can do heavy damage to infantery but in general it seems that champions is a decent choice against onagers+halbs.

Is it ever worth investing all these resources and time into the swordman line when facing a strong halbs+(siege)onager composition?