Topband: Measurements before and after connecting radials

[Gene Smar]

I plan to install a "significant" number of additional radials in my lawn to connect eventually to my shunt-fed tower on 160M.  Currently I have 7 18AWG radials connected to the tower and plan to add more from two reels of 500M long mil surplus twisted pair wire I bought in 2020.  I'll keep adding radials until I get tired or bored or run out of wire or lawn.  I'd like to see what quantitative effect this additional wire will have on the feedpoint impedance and, qualitatively, on my transmit efficiency (my rig's perceived signal strength at the receive end) as I add wires, maybe in groups of five or so.  

My question is this:  Would you expect there to be any impact on these measurements (impedance and efficiency) if I were to lay down the max number of wires on the ground at once, but connect only 5 or 10 at a time?  That is, will the mere presence of these wires in the ground in the proximity of the tower have any appreciable impact on my 160M performance even before I connect them to the tower steel itself?
Thanks for any insight you can provide.
73 deGene Smar  AD3F