Here's the thing with English Language-- I feel as if I wouldn't be absolutely confident in 3/4 if I didn't do 1/2 but at the same time, half of the 1/2 course is useless for 3/4 (I'm looking at you, language acquisition and history of English). You would be a bit behind picking up English Language without knowing the essentials about linguistics taught in 1/2 such as the subsystems and some metalanguage but if you truly love language and learning about its mechanisms then it shouldn't be a chore.
Literature is by far my most time consuming subject even though I am only doing 4 3/4s this year. If you believe that you can handle such a heavy workload and have the passion to do well in all your subjects, it wouldn't be too bad to do both. On a scale of 0-5 with 5 being the most time consuming, I would rate English language as a 1 or 2 and literature a 4 or 5.
Doing two Englishes is truly fun so pursue it if you believe that you won't regret it.