Team Scrub can either go really good or really bad. It all depends on whether the other player is mentally prepared to win a patience fight with you. If they’re going to start Cable, then your job is to gang up on him with both Sentinel and BH and get him off point without losing either of your two principals. Preferably by killing him, but one way or the other, you’ve got to exploit the fact that you’ve got two assists for your side and their Sentinel only has one. That’s generally the plan for any Cable/XXX/Commando… get their Cable of point and then work from the fact that Sent/BH/Commando usually has a serious advantage on any XXX on that team.
If they start Sentinel and try to rush at you (i.e. they’re not playing it patiently) you play it defensive and let him come.
If they’re truly prepared to win a patience fight with you though, they’re usually going to succeed. This is one reason why I still keep a Team Scrub of my own in practice; BH/Sent/Commando does much better against the overwhelming number of Magneto teams out there than it does against a stone-cold patient Cable/Sent//Commando.
However, there aren’t many people who are prepared to win a patience fight with me, so I don’t automatically stop playing BH/Sent/Commando when I see Team Scrub.
Run from Magneto. Take away the ground with a combination of j. fierce, Sentinel’s drones, and pokes, and force him to over the top where his offense is one-dimensional and one-directional. You will get the first solid hit a lot more often than he will, and he won’t survive the DHC. Then Sentinel can play with a lead, Commando and BH on Storm/Psylocke. This is almost always horrifically bad for Storm.
Start Sentinel. Spiral can win patience fights with BH just by remembering to block and pushblock. Sentinel and Commando don’t help him much on that. However, Sentinel/BH/any-AAA against Spiral is about the most one-sided matchup there is among the top eight or nine chars. Spiral has absolutely no chance in that fight. Let Sentinel maul Spiral and let BH hold the lead against whoever is behind her.
Start BH. If they’re starting Strider, play a patient running game and make him work hard for everything. BH has close-range reach advantage on Strider, teleport attacks are very dangerous to try on BH because any Commando hit that you anticipate getting because of the teleport can lead to a DHC that will most definitely kill Strider outright, and Strider simply can’t build the meter he needs to stay with BH if he only starts with the one he gets at the beginning if BH doesn’t get wild. As long as BH does enough damage to Strider that Strider can’t stay on point much after BH, Sentinel will win this fight against the rest of the team, because there’s no Strider/XXX/Doom combination where XXX/Doom or Doom/XXX is going to get very far on Sentinel/BH/Commando.
If they’re starting a battery char and putting Strider second, keep playing it defensive, use Sentinel’s drones to cut away the ground, and keep their first char from using Doom on you much. Sentinel’s drones should keep most any char other than Strider himself from getting a lot of usefulness out of Doom on this team, and if you play it carefully they shouldn’t be able to meaningfully chase BH down too much. Then Sentinel fights Strider later on, and goes trap versus trap. Trying to keep a Strider/Doom trap going on a patient Sentinel/BH is hellaciously hard.