Guys, do I need to keep track of which passport I entered the UK last time?

I am asking for me and my family where we are EU/US/AUS citizens and on top of that with the EU our country allows me to have multiple valid passport. So as a result I literally have 5 valid passports right now. I would not like to mix it up especially if it could create problems or confusion to the UK immigration. Our status in the UK will be tourist only.

Can I enter the UK on a different passport each time?

If the answer is yes, will I be perceived by the UK government as a citizen of the country's passport I just used to enter or will I be perceived as a multi-national of EU/US/AUS (if such a status exists in the British law). Also say I am alternating passports for each entry, is it OK to use the eGates or should I see an immigration officer for a stamp?