Mf/hf frequency preferences

Hello dear everyone !
İ am recently new member of this site after i made some researches about the subject that i had doubt about it.
İ am so confused about MF/HF frequencies to choose according to range. As i made research, wavelength shorten when the frequencies higher. So according to this, i wonder which frequency to choose when i want to make test call with short-range stations. Should i use 16804.5 or 2187.5 khz for short distance? İ am really so confused. İf range and frequency is inverse proportion so how can Hf has longer distance? İs that because it bounces from layers ? Also i found something like this;

MF/HF Range Freq. Day-light Darkness
2 Mhz 200 NM 500 NM
4 Mhz 400 NM 800 NM
6 Mhz 600 NM 1200 NM
8 Mhz 800 NM 1600 NM
12 Mhz 1200 NM 2400 NM
16 Mhz 1600 NM Fade Out

Also, i read that in the darkness low frequency is better, but here higher frequencies at darkness have larger distances as it can be seen in this table.

İ will join ship as an officer first time in my life, so i am so nervous about the subject that i have doubts. İ am sorry if i was silly with my questions.

Best Regards