I'll not disagree with you. Your 1st wheel is generated using two different wheels. I have an (18,6,3,6,7) which is not a split wheel mix. Strangely enough, your 1st wheel is better at 4if7 hits than mine. This observation is enough to understand that all (18,6,3,6,7) are not the same in terms of hits and this what I try to say. Possibly there are many better 7 ticket wheels.
Now, the inclusion of another ticket enhances the hits. I'll try to show some more in-depth analysis regarding the trade-off limit I mentioned above.
I'll describe an easy way to see (not mathematically strict) why the 3rd wheel (8 tickets) is not neccessary better even if we have more hits provided.
First of all, addition of this one ticket increases the cost by 8/7 tickets=1,1428 or 14,28% compared to the 7 tickets wheel.
I'll show that the addition of this line offers a better hit result but in fact the costs are greater than the possible earnings you expect by using this (18,6,3,6,8) wheel.
wheel 1 vs wheel 3 comparison (I omit x if 7 guarantee as this is not applicable to Pick 6 games and all 2 if x hits as they do not provide any prizes).
(x) is total to cover, -> improvement rate
3 if 3 : 128 - 152 (816) -> 2,94%
3 if 4 : 1398 - 1637 (3060) -> 7,81%
3 if 5 : 6888 - 7441 (8568) -> 6,45%
4 if 4 : 102 - 119 (3060) -> 0,55%
4 if 5 : 1212 - 1416 (8568) -> 2,38%
4 if 6 : 6252 - 7346 (18564) -> 5,89%
5 if 5 : 42 - 48 (8568) -> 0,07%
5 if 6 : 499 - 580 (18564) -> 0,43%
Compare the performance of increased rates the the increase of cost rate. No case is greater than 14,28% required to have a better hit ratio compared to the required increase of cost. Effectively this (18,6,3,6,8) wheel performs worse than the (18,6,3,6,7) even if it provides better chance to hit on higher prizes. This is what I try to say. No need to mention the (18,6,3,6,9); this is possibly even worse.
Here is another way (more mathematically strict) to see the same "phenomenal profit" of the 8 ticket wheel but if fact it provides worse results than the 7 ticket wheel.
1st wheel (18,6,3,6,7) hit ratio tables. The table shows the chance to have this wheel hit a specified prize after x draws (vertical axis)
3 if 3 3 if 4 3 if 5 4 if 4 4 if 5 4 if 6 5 if 5 5 if 6
01 15,69% 45,69% 80,39% 03,33% 14,15% 33,68% 00,49% 02,69%
02 26,45% 49,63% 31,53% 06,44% 24,29% 44,67% 00,98% 05,23%
03 33,45% 40,43% 09,27% 09,34% 31,28% 44,44% 01,46% 07,64%
04 37,61% 29,28% 02,42% 12,04% 35,81% 39,30% 01,93% 09,91%
05 39,64% 19,88% 00,59% 14,55% 38,43% 32,58% 02,40% 12,05%
06 40,10% 12,96% 00,14% 16,88% 39,59% 25,93% 02,87% 14,07%
07 39,45% 08,21% 00,03% 19,04% 39,65% 20,06% 03,33% 15,98%
08 38,01% 05,10% 00,01% 21,03% 38,91% 15,21% 03,79% 17,77%
09 36,05% 03,11% 00,00% 22,87% 37,58% 11,35% 04,24% 19,45%
10 33,78% 01,88% 00,00% 24,57% 35,85% 08,36% 04,69% 21,03%
11 31,33% 01,12% 00,00% 26,12% 33,86% 06,10% 05,13% 22,52%
12 28,81% 00,67% 00,00% 27,55% 31,71% 04,41% 05,57% 23,90%
13 26,32% 00,39% 00,00% 28,85% 29,49% 03,17% 06,01% 25,20%
14 23,90% 00,23% 00,00% 30,03% 27,27% 02,26% 06,44% 26,41%
15 21,59% 00,13% 00,00% 31,11% 25,08% 01,61% 06,86% 27,53%
16 19,41% 00,08% 00,00% 32,07% 22,97% 01,14% 07,29% 28,58%
Now follows the same tables for the 3rd wheel (18,6,3,6,8).
3 if 3 3 if 4 3 if 5 4 if 4 4 if 5 4 if 6 5 if 5 5 if 6
01 18,63% 53,50% 86,85% 03,89% 16,53% 39,57% 00,56% 03,12%
02 30,32% 49,76% 22,85% 07,48% 27,59% 47,82% 01,11% 06,05%
03 37,00% 34,71% 04,51% 10,78% 34,55% 43,35% 01,66% 08,80%
04 40,15% 21,52% 00,79% 13,81% 38,45% 34,93% 02,20% 11,36%
05 40,84% 12,51% 00,13% 16,59% 40,12% 26,38% 02,74% 13,76%
06 39,87% 06,98% 00,02% 19,14% 40,19% 19,13% 03,27% 15,99%
07 37,85% 03,79% 00,00% 21,46% 39,14% 13,49% 03,79% 18,08%
08 35,20% 02,01% 00,00% 23,57% 37,33% 09,31% 04,31% 20,01%
09 32,23% 01,05% 00,00% 25,48% 35,06% 06,33% 04,82% 21,81%
10 29,14% 00,54% 00,00% 27,21% 32,52% 04,25% 05,33% 23,48%
11 26,08% 00,28% 00,00% 28,77% 29,86% 02,83% 05,83% 25,02%
12 23,15% 00,14% 00,00% 30,17% 27,19% 01,86% 06,32% 26,44%
13 20,41% 00,07% 00,00% 31,41% 24,59% 01,22% 06,81% 27,75%
14 17,89% 00,04% 00,00% 32,51% 22,10% 00,79% 07,29% 28,95%
15 15,59% 00,02% 00,00% 33,48% 19,77% 00,51% 07,77% 30,05%
16 13,53% 00,01% 00,00% 34,32% 17,60% 00,33% 08,24% 31,05%
Now, if we play 7 times the wheel (18,6,3,6,8), we can play 8 times the (18,6,3,6,7) wheel with the same cost because in 7 draws, we'll play 7 more tickets in total using the (18,6,3,6,8) wheel. Thus we can play once more at the same cost using the (18,6,3,6,7) wheel.
Now, lets compare the hit ratios tables of both wheels including the above comment.
3 if x hits: the (18,6,3,6,8) provides slightly better hits at the beginning.
Especially for 3 if 5 will "surely" hit once in 3 or 4 draws. So, In 8 draws, you'll hit twice or more using both wheels and at the end you'll have a free additional play for the (18,6,3,6,7) wheel = 1 free more chance to win! All other 3 if x have about the same property but less obvious. Still, you'll have a free 1 more try for (18,6,3,6,7) after 8 draws based on the above comment.
5 if x : these are out of question as the hit rates are rather low to say (18,6,3,6,8) offer better performance at the long run.
4 if x : things are more complicated here but still you can see that the benefit is not really huge at 8 consecutive draws (and therefore you gan 1 free (18,6,3,6,7) wheel to play).
Hope this makes things more clear.