What is the index play logic for the following deviations?

[Three]

Ok if my simulations are wrong that I invite someone in this forum to check them.

There is no need. Norm already did it in this link in graphical form for hilo:

https://www.card-counting.com/cvcxonlineviewer3.htm

Set the input to the desired hand matchup and then take the values at the halfway points between the lines for the EV at each TC. You will see yours are less than half the EV's that have been accepted from sim data for years.

[Phoebe]

Ok if my simulations are wrong that I invite someone in this forum to check them.

According Norm himself, numbers in index generation report are not EV. Look at software forum.

[Meistro123]

You have to expect to lose this hand whether you hit or stand. You generally have less than a 25% chance of winning with 16 or 15 vs T or Ace (especially vs A in H17 game). Ultimately it's not really a matter of understanding these plays logically, proper strategy is determined through simulation.