Its not so much if the node succeeds, but when it succeeds. that is, unless the hacker is god and the target is 1+1 toy.

And at that point, i suspect the GM could simply allow the hacker to buy successes rather then roll (4:1 ratio).

A good hacker (18 dice exploit is not hard, if that's your specialty), hacking admin on a rating 4 commlink with rating 6 stealth wins in less than two rounds, where it takes him two and a half to get noticed. Using edge can get you to win even against a rating 6

So, the reason I say to manually Cross-Reference upthread is that when you draw lines from the Actions to the Programs and back, you learn which Matrix Actions anybody can do at any time, and which require specific Programs. You also learn which programs do only one thing:

Armor, Attack, Biofeedback Filter, Black Hammer, Blackout, Browse, Data Bomb, Decrypt, Defuse, Disarm*, ECCM, Edit, Encrypt, Medic, Nuke*, Purge*, Reality Filter, Stealth, Track

Which programs do two subtly different things:

Analyze, Command, Corrupt*, Scan, Sniffer

and which do several different things:

Exploit

*Programs from Unwired.