Bosch, 39 Tests, said in a column in The Rugby Paper that having their first two games against a South Africa team which is the best in the world when playing without the ball.
"They are horrible in terms of the pressure they put you under in every aspect of the game. South Africa are now playing a style of rugby which really suits them," he said.
When facing the All Blacks on the Gold Coast, they will have a different challenge.
"The All Blacks are, of course, still a very strong team, but I don't think they are at the same level as when I was still playing the game.
"They had some awesome combinations in the past – the likes of the back row which comprised Jerome Kaino, Richie McCaw and Kieran Read. That also had Ma'a Nonu and Conrad Smith in the centre, which was a great combination.
"Nowadays, the All Blacks have very talented players but I don't know if they are as solid as previous All Black teams.
"To be the best team and win big games on a consistent basis, you need something more than good individuals.
"Los Pumas, whose confidence was knocked against the Springboks, can cheer themselves up by reviving the recent memory of having defeated the All Blacks 25-15 during the 2020 Tri Nations tournament," he said.
Argentina had played one of their best Tests after the most unusual circumstances of not having played any games while preparing for the tournament.
"However, things move on, and it's been nine months since that historic game happened.
"Both teams are now in a very different situation. I don't know if the All Blacks are on the same level they used to be five years ago when they were dominating world rugby.
"Nowadays, the second-ranked All Blacks are not dominating as much but are still a top team," he said.
However, Argentina needed to improve their discipline and their set-piece heading into the remainder of the competition.
To challenge the All Blacks, they need to gain parity at lineouts and scrums, he said.
That would also be a test for the coaching duo of Mario Ledesma and Michael Cheika.
"Los Pumas were pretty good on defence against the Springboks and we didn't see a South African team with ball in hand really gaining yards and going forward. However, Argentina pride themselves on their attacking play and need to build on that aspect against New Zealand and Australia," he said.
The All Blacks had been unstoppable against Australia.
"When you make a mistake against the All Blacks, they make you pay in cash," he said.
The All Blacks take on Argentina on Sunday 12 September at 7.05pm NZT at Cbus Stadium on the Gold Coast.