FW doesn't require tons of trains everywhere to be viable. In fact you can get it over level 50 with +straight skill items.
Put one of these on a merc to make him weaken the shit of npcs (read: makes him tankier)
http://diablo2.diablowiki.net/The_Reaper's_Toll
Firewall lvl 50+ is like 20k+ damage PER SECOND.
Did I mention it doesn't take tons of trains spent all over the place in other skills to make it viable? Shit :P.
Oh -- it will likely make for a terrible bot.
But I don't get down like that.