this season it would hurt Rachel or Sam if they weren't involved and it was Teeny and Sue battling it out.

If Sam builds and Rachel doesn't, Sam can use it as another example in an "I was constantly on the bottom and kept battling" argument. It wouldn't put him over the top per se, but it would give more substance to the argument. Esp if he goes against Sue, because it would take out some of her loyalty votes (Gabe?, Caroline?) that wouldn't vote for Sam if Sue was still in but might if they are choosing between Sam and Rachel.