New rider hunting best options. Component swap from sale bike?

[UnopenedEnvelope]

Hello! new to the forum and new to riding (save some silly forrest riding when i was a kid in the UK)

I am looking at Polygon as a brand as they seem to offer good value for money.
I was comparing their 2018 Xtrada 8 vs their Siskiu29 9.
It seems the Siskiu beats the Xtradas components all the way through (please confirm?)

https://www.bicyclesonline.com.au/2018- ... dMEALw_wcB

RockShox Recon RL Air fork 100mm travel
Entity Void Saddle CroMo rails
Entity Expert Alloy seatpost
Prowheel Charm 32T T 2 piece crank
Sunrace 11 speet 11-46T cassette
Shimano Shadow XT RD M800 with clutch 11 spd derailleur
Shimano BL M365 Hydraulic disc brakes
Schwalbe Tough Toms

VERSUS

https://www.bicyclesonline.com.au/2016- ... ntain-bike


Rockshox Reba RL with Remote Lockout, Tapered Steerer and Thru Axle
Entity Flux, Steel Rail
Entity Xpert, Alloy, 30.9x400mm
Shimano XT FC-M8000, 170mm(S-M), 175mm(L) 36x26T
Shimano XT CS-M8000, 11-40T 11 sp
Shimano XT RD-M8000GS
Shimano SLX BR-M675, Hydraulic, 180mm(F) 160mm(R)
Schwalbe Rapid Rob, 29”x2.10”

etc etc. Am i right in thinking the Siskiu is bettter?

THE PROBLEM
Both are currently the same price as the Siskiu is only in size SMALL and on sale.

THE QUESTION (may be stupid)
Would it be worth considering buying the siskiu for the components, and purchasing a frame large enough for me? Or, another silly idea, buy the siskiu, and ANOTHER donor with poor components but great frame and do a component swap and sell the other?

No idea if im in fantasy land, but would quite like a bike soon and these seemed the most suited.
FYI i'm 187cm 110kg, would be most likely road riding or light trails with my partner or friends and commuting to sports training across the city through parklands.
I like the idea of local MTB trails and could see myself getting into it a little, with lessons, in WINTER (scorching queensland summers are not my friend). Family live near large reserve with bike tracks and fire trails that Id like to try...

Any advice or ideas appreciates
Heckling and abuse tolerated
sarcasm expected

Thanks All
Unopened Envelope

[Ross]

I would think the cost would be prohibitive to buy a bike just for it's drivetrain and then to buy another frame and swap all the stuff over and make a complete bike out of it. Depends if you can do some or all of the mechanical swapsies yourself or if you need to get a LBS to do it (some LBS don't like/won't touch components sourced from other places)