Guilds/Companion planting question - sanity check needed

Calling all smart people!
This post https://permies.com/t/57382/Apple-guild-part-series-videos contains a plant guild chart. by the Urbania Hoeve. I had never seen it done that way so I decided to go over it and see how I can do something similar and more detailed for what I am working on so it's quicker/easier for me to set up my garden this spring. Reading off my typed up list is just a pain in my experience. The thing is though that I ran into something odd.

All my research on guilds/companion planting states that tomatoes should NOT be planted need potatoes. However the attached guild chart shows that tomatoes and potatoes are both in the Solanacea family. So why does the chart seem to imply you can/should plant them together?

Also from my research: tomatoes and lettuces grow well around each other. However this guild chart says that the Solanacea family (tomatoes) should NOT be planted near the Asteraceae (lettuce) family.

Am I having a blond moment here and just not understanding how to read the chart correctly or could this guild chart be off a bit?

Thanks in advance for sharing your thoughts and experiences.

They are closely related, so they pass diseases and probably pests to each other.

There must be someone out where in Permie land who can clarify if this chart if valid or not???

Oh, my apologies. I must have totally misread your post... Tomatoes and potatoes are related enough to pass diseases.

I have a big copy of that chart on my wall to learn it too. My opinion (and it may be wrong) is it's a good base, but only a base. I look at it and say "ok, this family might not like them in general, so if I can I'll give them space,  but if I need to put them near each other, I'll try it and see what happens."  

But I'm not educated enough in all of this to be able to say if the chart is totally accurate, My guess is no, but it's a good start, and there are always exceptions and local conditions.

This is just my opinion, but that chart is WAY more complex than it needs to be.  I have had good results making my guilds by starting with any central tree I like and planting a large variety of different plants around it based on their size and the layer they will occupy.  If I had to concern myself with every possible plant interaction I would just give up.  As far as plants from the same family being planted together or not based on whether they can share a disease, I look at it this way.  Tomato and potato might share a disease, so they shouldn't be planted together in a guild?  What about the 100 potato plants I put next to each other in this year's potato patch?  Should potato plants not be planted next to each other?  I may get better results if I had no plants from the same family or that share the same pests next to each other, but from a practical standpoint, it would be very complex and cumbersome to worry about, so I don't.  If you plant something in a guild and it doesn't do well, you can always plant something else there next time.  If a plant is struggling, pull it out and plant something else.  My personal view is that is you are feeding the soil well, your plants will take care of themselves with minimal problems.