I'm assuming ur asking about how much workload for each subject?
In that case, i can talk to u abt all except chem (i did eco in yr11, but dropped for yr12)
Lets start of from the top.
1. ext 1 english. So i acutally don't think there is a lot of work for ext english lol. for our cohort we just had one test, and the rest was assignments/presentations. you have an irp (indepedent research project) as ur last assessment - tho im not sure if you will, and its really just public speaking, reading off an essay lol. The first assessment was the hardest, that one was an actual in the hall assessment so you might need to memorise (for us it was an creative, not an essay). Other than that I felt the course was acutally pretty fun (we got to do parasite as our text LMAO)
for yr12, same thing, we had one assessment (another creative which you can reuse from yr11 if it fits the q) and a handin essay on franekntesin and a related text
2. ext 1 maths, so i feel like if you are good with maths/go to tutoring which goes ahead, then it should be a breeze. What i will say though is that if you are looking to do 4u next year, then focus a lot on ext 1 maths. For our cohort the weighings was 70% ext1 and 30% adv (ofc idk waht ur school does_). But i would definitely say spend mroe time on maths in yr11 since it may (or may not) impact ur subjects next yr. (wait i jsut realised those were ur subjects for yr11-12 oops but ill just put it here anyways) Just saying that maths was the only subject that influnced what subjects we could take for hsc
for yr12 oru school hasnt done all the harder topics, like combinatorics, stats, probablity, so so far it hasnt been too difficult, i would say integration is a major topic / compared to differentiation in uyr11 and both should be pretty easy so if you can get those two topics down i can cover around 20-30% of the test already (trig is another importatn one)
3. adv maths should be easier than ext1, so i would assume spend less time on that, just do more past papers since the questions are relatively basic. ( i dont do adv maths in yr12 since i do 4u, so icant say much. however my friends - who are respectively ranked 80/140 and 130/140 for ext1 got 98% and 89% for advanced assessment)
4. Adv english is definitely a struggle if you do not have a tutor/a willing teacher/if ur weak at the subject. For y11 it was kinda chill, but once it got to yr12 it really shifted (i would say its on par with ext1 maths). For context, I just had/am currently in my assessment block and for english i had to memrosei 4000wrods...ofc some people may do it differnetly, but if you want to be fully prepared, be ready to dedicate a lot of time on english. But once you have ur essays done and memroised, it should be a breeze since what your doing for the entire year is jsut prepping 3 essays 1 creative/discursive.
5. physics is relatviely content heavy, there are calcuations (i.e. mod 5,6 but once u get to mod 7 it is a lot of rote learning, more like a history lesson lmao) but once you understand the concepts (which there are a lot), then do questions to fill in holes / common miscocneptions. I.e what is the reaction for the wieght force of an object, its the gravitational pull the object exerts on the earth. (most people will say normal force)
6. eco - i only did yr11 eco, and i struggled quite a bit to keep up, I sort of lost my excitement for the subject and hated to go to each class cus iw asnt really good at it (hence why i dropped out), but yea the start was pretty managable, but eco is defintely a subject that is content heavy (far moer than phys i would say) a lot of rote learning to be done. Overall doable, jsut wasnt for me - i did maths in eco isntead and got a teacher to write me a letter so i can explain to the library assistant that i was there jig classlol
hopefully that helps, lmk if you want mroe clarification, but generally you might want to consider dropping one subject (ik u said eco), all ur subjects are pretty heavily relied on memrosiation. that leaves you 10units though, so i would implore you to look into 4u maths if you can. it helps with ur atar in terms of scaling but if maths is a weak point then it shou'dnt be a priority. just a suggestion!