There are many different combinations of parts that will achieve the same end result. While 72 MHz does follow the same rules as real RF the wavelength is so long it takes a lot of change to notice much of a difference. I have not looked at the schematic for the RX we use but if I were laying it out I would make the front end pretty forgiving to the antenna impedance. The antenna is subjected to all kinds of abuse in the normal everyday world from getting a few inches chopped off, to sitting next to a steel pushrod, to being less than fully extended. It really is very forgiving when you think about it. The last thing most of us need is a RX that is tuned so tight on the front end that chopping off a few inches of antenna wire will cause a significant change in range and if the front end is peaked like that you can forget about changing out the crystal. As far as believing old wives tales I don't think it is me that is buying into them. The evidence is there to observe, the RX front end is tuned to accept a relatively wide band width.
Here is a link to an easy to use and understand calculator for anyone that wants to play around with wavelengths and frequencies.