You can watch the Bahrain–Curaçao match here if interested.
Watched first 8 mins. Curacao actually hit the post at 4.30mins approx in.
0-0 until HT & 1-0 until 84 mins. So final 4-0 scoreline likely misleading.
Bit like AWs, Curacao have some guys at a high level, and then some down in 3rd-4th tier/U21 football. Some at even lower levels than the AWs.
So if Kluivert made a heap of subs as per normal in a friendly, their team that finished the game may have been a big drop in quality from the starters. He's likely experimenting too, as a fairly new coach (replaced Guus Hiddink this year), with no major CONCACAF comps again until 2023??
Bahrain on the other hand have the Arab Cup, coming up in December. So perhaps a bit more in serious mode currently, with less dabbling.
Edit - see Curacao started their big guns Bacuna bros & Anita. Roly didn't start.
https://www.sofascore.com/team/football/curacao/55827
https://int.soccerway.com/matches/2021/10/06/world/friendlies/bahrain/netherlands-antilles/3661687/
Curacao started with this experienced eleven, several currently in the Eredivisie or with sizeable clubs; the six second half subs were aged 30, 28, 25, 23, 19 and 18 (see details below):
1 | Z. de la Paz G Oakland Roots (USL, second tier; former Oldham Athletic #1)
2 | C. Martina D Unattached FC (captain; ex Everton, Southampton)
5 | S. Alberto D Pabdurii, Romania (ex Sparta Rotterdam)
13 | J. Gaari D RKC Waalwijk, Eredivisie
8 | V. Anita D RKC Waalwijk (ex Newcastle Utd, Ajax)
10 | L. Bacuna M Cardiff City (ex-Aston Villa, Premier League)
21 | A. Statie M Kozakken Boys (Dutch 3rd tier; mostly played in 2nd tier)
7 | J. Bacuna M Glasgow Rangers (prev. Huddersfield PL & Champ.)
9 | R. Janga F Apollon, Cyprus (ex NEC, Dutch 2nd tier; Lugano, Swiss top tier)
17 | B. Kuwas F Maccabi Tel Aviv (ex Heracles, Eredivisie)
14 | K. Gorré F Boavista, Portugal (4th season in Portuguese top tier)
Six subs by Curacao in the second half: two at 46 m., three at 63 min., one at 86 min.: G Kastaneer, 25 yr old PEC Zwolle striker 46 m.; B. Martis, Celje, Slovenia 46 m. (23 yrs, ex Sparta Rotterdam defender); J Antonia, NAC Breda 63 m.(Dutch 2nd tier aged 30); N Holder, Groningen u-21 63 m. defender aged 19; G Nepomuceno, PFK Cherno, Bulgaria 28 yr forward (ex Dynamo Bucharest, Oldham Athletic) 63 m.; A Leito, PEC Zwolle u-21 forward aged 18 at 86 min.