What’s at stake: NBC’s hospital comedy takes on one of the fall’s most promising new laffers in ABC’s “Rodney,” starring Rodney Carrington as a standup comedian juggling his career and family life. It’s hard to imagine that two comedies could have less crossover audience than this pair, suggesting that both could survive quite nicely.NBC perspective: “Scrubs,” popular with young adults but never a broad hit, has bounced back and forth between the net’s Tuesday and Thursday sked but looks better in this Tuesday slot, where there’s less pressure and a lower rating can still be considered a success. Coming out of untested but seemingly compatible new laffer “Father of the Pride,” this fourth-year comedy should challenge for the 18-49 lead and possibly prevail in 18-34. ABC perspective: In a return to its more blue-collar Tuesday comedy roots, “Rodney” seems like a good fit with “According to Jim” and will benefit from heavy promotion during “Monday Night Football.” Net has not had a really strong show in this 9:30 slot in nearly 10 years, but this reps perhaps its best shot since then. Look for it to play well across the 18-54 demos in Middle America, among both men and women. Bottom line: By playing to different audiences and meshing well with their lead-ins, both “Scrubs” and “Rodney” should become strong performers in a timeslot without a lot of tough competish otherwise.