Is This a Valid Combo? from $78 48GB over 14months or $99 78GB Data $60 Credit over 15months

So i was reading through these 2 prepaid sim "hacks" and identified this potential combo below that nets you 40gb data over a long expiry.
Can someone please validate if this would theoretically work?

https://www.ozbargain.com.au/node/416717
https://www.ozbargain.com.au/node/399647

Using these two ideas, could you buy the $40 prepaid sim pack that is currently on sale for $15, recharge once using the $30 plan and get the Prepaid Max plan which nets you:
18gb data + 8gb and 22gb bonus in the second month into your data bank
= 48gb data

Then after the second 28 days, recharge with the Long Life Plus plan
you can choose $30 for 186days or $70 for 365 days

assuming you do the $30 recharge, thats $30 credit for 8 months total with 48gb data for net cost of $75
($9.375/m for 6gb data per month + $30 credit that can be used for calls for 8 months)

similarly you could do:
1) $15 starter + 1 x $30 prepaid plus recharge + 2 x $30 long life recharge that will last 14 months and get $60 credit and 48gb data, costing $105
($7.5/m for 3.42gb data per month + $60 used for calls for 14months)

2) $15 starter + 1 x $30 prepaid plus recharge + 1 x $70 365 recharge that lasts 13 months and get $70 credit and 48gb data costing $115
($8.21/m for 3.42gb data per month + $70 used for calls

3) You can always top up with 5 cycles of recharges to get 150gb total bonus data for $15+ $150 first then do a 1x$70 365 recharge to get 168gb data costing $235 which will last you 18 months
$13/m for average 9.3gb data/m + $70 used for calls in the last 12 months, first 6 months is unlimited calls and text

4) if you wanted something more frequent then then 3) above with $30 recharge:
$15 + $150 + $30 = $195 lasting 12 months
$16/m for average 14gb data per month + $30 used for calls in the last 6 months. the first 6 months will be unlimited calls and text

The fourth one is starting to see less value if you need to make alot of calls

All of the above is assuming you dont text and call that much (which i dont and mostly use skype/wechat/whatsapp)

All of the above can be even cheaper if you buy discounted recharges using ebay recharges https://www.ozbargain.com.au/node/399647

I cbb doing the math using discounts but its roughly at least $21/recharge so total of $15 + 5x$21 + $70 = $190 instead of $235 for scenario 3) above
so $10.56/m instead of $13/m for 9.3gb/m data on average
or $150 for option 4) 12 month version

can someone tell me if this combo is valid?

the belong hack is simpler netting you equivalent to option 1 but costs $150 if you rely on 3 x half price 15gb sims