What datasheet should I trust for TIP 35 and 36?
You should know that the current amplification factor \$\beta\$ or \$h_{fe}\$ is of bipolar transistors almost never has a very predictable value.
Go look in the datasheets of these transistors (or any other bipolar transistor!) and look at the minimum and maximum values of \$h_{fe}\$. For example in this datasheet when \$I_c\$ = 15 A, \$h_{fe}\$ can vary between 15 and 75, that's a factor 5!
The measured plots that you find in the datasheet are for a &quot;randomly&quot; selected transistor. I write &quot;randomly&quot; because of course they will choose a transistor that has a \$h_{fe}\$ that is very close to the average value that the manufacturer expects.
In a simulator model you will also get a value of \$h_{fe}\$ that is typical and average.
By no means can you expect that all the transistors that you buy, even if they were made by the same manufacturer, will have a \$h_{fe}\$ that is close to the typical value. The manufacturer could only guarantee that if they would measure each device and sort the transistors on their \$h_{fe}\$. Then a lot of transistors would then have &quot;a un-typical&quot; value for \$h_{fe}\$ and the rest would have to be discarded. That would make the remaining transistors very expensive!
But is it really an issue that \$h_{fe}\$ isn't very perdictable?
I would reverse it and state that if your circuit design needs a transistor with such a tightly controlled value of \$h_{fe}\$, then you're not doing a good job as a designer.
In most commonly used circuits, generally only a value of \$h_{fe}\$ that is too small will be an issue. When \$h_{fe}\$ is too small then it is possible that the transistor will enter linear mode when it needs to operate in saturation mode for example.
If \$h_{fe}\$ is larger than expected, usually only less base current will flow and that generally is not an issue. So what experienced designers do is figure out what minimum value for \$h_{fe}\$ they can expect and then design their circuit for that value.
TLDR: You should trust the datasheet of the manufacturer of the device that you're actually using. If you're using devices from many manufacturers, trust all of them to be true and look for the minimum value of \$h_{fe}\$ and that's the value you should be using in your design.