Where did I go wrong?

[Brian_]

Yes. Even in heavy rain, archers will massacre warrior monks on a bridge.

Well, that was my concern. That was why I charged with my diamyo/Yari first, to take the brunt of the missile attack. I was hoping the Monks would be spared most of the arrow fire, and truth be told, I don't believe it was the arrows that caused them to panic. I think it was the subsequent charge by the enemy yari/ashigaru...

I guess I thought the Monks were going to be more stalwart than that...

[Sasaki Kojiro]

I think the units defending the bridge get a defense bonus or something like that as well.

With shock units like monks, it's a feel thing when deciding whether to charge straight in or flank. Against ashigaru you can hit them head on, against decent honor yari samurai, sometimes it is better to flank. Make sure you get the charge.

Rest assured, they can crush the enemy...

[gollum]

hello brian_,

bridge battles are a grinder, make sure you bring along a few yari samurai (or naginata if you have them) to cross and fight first before sending in the shockers to rout the enemy. Send as single units of YS at first and once they are routed let them recover at the back and send in a new one. Back them up with arrow fire (or guns if you have them), the AI makes a large blob of his units in an effort to defend effectively and overwhelm whoever crosses, but this makes them vulnerable to your arrows. Shoot into the blob and although your YS will get casualties, the enemy's hopefully will be more, since you will be sending them one by one but the AI alltogether. In addition, as the AI foot troops will get tired from the running and fighting, your fresh units will last longer and longer against them, grinding them down due to fatigue even more.

At this stage that you feel the enemy has been grinded down enough, send in the shocks: WM, Naginata's or Nodachis and any YS units that have recovered. Hopefully the enemy arrows will have been depleted by now too. Send them all at once to get the number morale scales even and if possible rush them as far in after the bridge as possible to gain space so you can engage as many as possible simultaneously. If you wish to bring the general/daimyo, let him come last behind them, so he'll be the last to engage - all you need from him is his presence.

In the early stages of the game there are many exploiting tactics to win bridge battles easily against the AI; one of them is to cross with the Daimyo Hatamoto's and make a circle to the enemy backs attracting their attention, and at that particular moment make your yaris cross. Once the enemy returns and engages you, backstab their melee troops with the Daimyo. This works mostly very early in the game when the enemy troops are few (3-4). DOnt attempt it if your enemy has more than that and you have no heir, because it may take you another life to succeed.

[Yesugey]

Even one single salvo of the SAmurai Archers can kill +15 of the Monks, i've seen +20 lots of times. (120 men per unit) Even few Monks survive, they will be highly demoralized.

So even after your YS, never sent your Monks under an arrow fire, train Naginatas instead. (As Sasaki Kojiro said, running with your Daimyo to absorb the arrow fire is a bit of cheating.)

But i dont think defenders have any other bonuses, we feel that way because our crossing men feel alone and wavers much more quickly.