The two-week break between the end of the first leg of the Nations Championship and the arrival of the All Blacks for the Rugby Greatest Rivalry tour feels like the calm before the storm as the respective coaches and squads intensify their focus on the big event of the year.This time in two weeks we will have seen the first game of the tour, with the starting game against the Stormers on Friday, August 7, as well as the Springboks’ warmup Test against Argentina in Buenos Aires. Once the series starts on August 22, it is going to be a hectic and murderous schedule, with four games played over four consecutive Saturdays.There is a lot of justified positivity coming out of New Zealand following the excellent win over Ireland, and the Boks will have considered themselves warned by that performance. However, when Rassie Erasmus named his Bok squad of 43 that will work on the next phase of the buildup — it is not an official Rugby Greatest Rivalry squad as yet — it underlined why the hosts will go into the series as clear favourites.Four matches in four weeks means the likely intensity, physicality and tempo of each match will take a lot out of the players. It is hard to see how either coach can expect to get through that schedule with the core of just one team fronting each week, and the Bok squad reflects the depth that was successfully tested in the three Nations Championship games.While Dave Rennie, as a new coach for the All Blacks and in the interests of bedding in his systems and combinations, fielded pretty much the same team in each of the games against France, Italy and Ireland, his Bok counterpart made significant changes for every game.Because of the emergence of new players, Erasmus has the kind of headache to face down that all his adversaries would envy. It is headlined by the choice he has to make at openside flank, where Paul de Villiers’ brilliant transition to international rugby has placed pressure on skipper Siya Kolisi.Which is exactly what Erasmus would have wanted, and the same can be said for the form shown by two of the locks who played in the absence of Eben Etzebeth and Lood de Jager. The two veterans are back in the squad now, but will need to play well in the August 8 clash with Argentina to get the nod ahead of Cobus Wiese and Ruan Nortjé.The two veterans are back in the squad now, but will need to play well in the August 8 clash with Argentina to get the nod ahead of Cobus Wiese and Ruan Nortjé.Indeed, the fact that Ruben van Heerden, who was excellent in his debut Test against Wales, is not in the squad, and this at a time that RG Snyman and Salmaan Moerat are both unavailable, is an indicator of just how deep the pool of lock talent is. And it was supposed to be a problem area. That there are only three specialist locks listed underscores one of the biggest advantages Erasmus has — the interchangeability of players between positions.Players who have played most of their rugby at lock feature among the group of utility forwards and loose-forwards — Wiese and Franco Mostert, while Ben-Jason Dixon (loose-forward) and Pieter-Steph du Toit (utility forward) can also double up.It is at the centre, though, that the benefit of utility value is particularly evident. There are three centres listed, with the regular midfield pairing of Damian de Allende and Jesse Kriel joined by a fit-again André Esterhuizen. Yet that isn’t the sum total of Erasmus’ midfield options, with Canan Moodie, Ethan Hooker, Damian Willemse and indeed Handré Pollard all having been used there.It is interesting to note that the two biggest wins the Boks have scored against the All Blacks were the 43-10 triumph in Wellington last year, when Willemse and Moodie lined up at centre, and the 35-7 win in a World Cup warmup game in London in 2023, when Esterhuizen and Moodie were the midfield pairing.That is the type of interchangeability the Boks possess, something that will give Erasmus the kind of scope to keep his team fresh by managing his players that Rennie won’t have to the same degree. Over a four-game series, that could be the telling difference.