"A cavalry charge can only succeed...

[Volcano Man]

Can they catch alot of setting up direct fire guns and machine gun units"

If that is a question, yes, certainly they can especially if they are unsupported and keeps people from being be overtly and a-historically aggressive with them. This goes back to your other thread about why these units (Field Guns and MGs) had to have some special setup process (but not an actual "set up" status) to make them vulnerable and prevent them from being some rapid deployed death ray. :eek1:

So, how effective are/is/was cavalry in World War One? Well, it all depends on the circumstances and whether or not the enemy gives (or gave) the other side an opportunity to have a successful charge. Historically, the commanders on both sides were good enough to minimize the success of cavalry by being, well, cautious.