Automatically Add to and Tally a List

I am starting with a property list in column D and adding owners to it in columns E (First) and F (Last). As I add the owners I'd like to have an additional list tallying the number of buildings owned by each owner.
Essentially an auto remove duplicates and countif. Any assistance would be greatly appreciated.
Thank you!

Maybe like this:

Helper column: =B2&" "&C2
Unique: =IFERROR(INDEX($D$2:$D$17,MATCH(0,COUNTIF($D$2:$D$17,"<"&$D$2:$D$17)-SUM(COUNTIF($D$2:$D$17,G$2:G2)),0)),"") and drag down, array entered(Ctrl+Shift+Enter instead of regular Enter)
Count: =SUMPRODUCT(--($D$2:$D$17=G3),--($A$2:$A$17<>""))

PaulM100 this is a great start! If I want to keep adding to the list, do I have to keep changing the absolute number in formula or can I predetermine that to more than just row 16?

You can change the 17 with , let's say 1000 or 2000 for now and you can increase it afterwards, in the formulas. If you select the entire column as range it will slow down in time. At least, this is my opinion.

see attached for my list

is not attached

something attached?

Yeah. I will take a look on it

in Helper column add this: =TRIM(E4&" "&F4) and drag it down as necessary
in Count tab, B3 use this: =IFERROR(LOOKUP(2, 1/((COUNTIF($B$2:B2, Data!$A$4:$A$1500)=0)*(Data!$A$4:$A$1500<>"")), Data!$A$4:$A$1500),"") (is not array)
in C3: =IF(C3="","",SUMPRODUCT(--(Data!$A$4:$A$1500=B3),--(Data!$D$4:$D$1500<>"")))

Drag down as much as needed for all of them. Do not forget to change the ranges once you've reached row 1500

This is great! Thank you