Australia are back home and have began their two weeks' quarantine. They will have plenty of time to reflect on a tally of two wins and eight defeats in ten T20Is over the last month in the West Indies and in Bangladesh. There was a one-day series victory in the Caribbean which was not insignificant, but in terms of the immediate priority, it was a sobering experience.

The caveats around the tour have been well documented, yet even with key players missing, it was hardly an outcome to instill confidence with the T20 World Cup two months away. The guarded warnings ahead of the trip that those declining to tour were risking their spots does not carry much weight now.

"For guys to be on this tour to get the first opportunity to put their hand up and take that spot is what it's about," Aaron Finch had said before the series in the West Indies. "It's tough to ignore really good international performances."

A lot of the batting numbers make for grim reading, even factoring in the tough conditions in Dhaka. Moises Henriques (135 runs at 13.50), Matthew Wade (129 runs at 12.90), Alex Carey (57 runs at 8.14), Josh Philippe (33 runs at 6.60), Ben McDermott (66 runs at 13.20) and Ashton Turner (51 runs at 10.20) have not had trips to remember.

Given their experience, it is the first three of those that are of most concern, although the others raise questions about how the BBL is preparing players for the step up. Australia's T20I results have gone backwards - five series defeats in a row - in the Covid era, which has required a greater depth of resources in expanded squads and to fill gaps of absentees. That No. 1 T20I ranking now feels a long time ago.

Conditions in Bangladesh were at the extreme end, and it is worth noting the home side acknowledged that as well, but it is about finding a way. Only Dan Christian's promotion to No. 3 in the fourth game, Australia's lone victory, suggested the agility to respond to the challenge; but it was already 3-0 in favour of Bangladesh by then. With a series win in the offing, the hosts had a batter make the difference in each of the first three games: Shakib Al Hasan with 36 off 33 balls in the first T20I, Afif Hossain with 37 off 31 in the second and Mahmudullah with 52 off 53 in the third.

With a view to the World Cup, the five matches in the West Indies were perhaps a little more instructive, and that was a 4-1 margin as well. Those surfaces were probably closer to what will be on show in the UAE despite the volume of matches that will be played in Dubai, Abu Dhabi and Sharjah with the IPL taking place beforehand.

Even in the match Australia won in St Lucia, based around a 114-run stand between Finch and Mitchell Marsh, there was a middle-order stumble that was halted by Christian. It almost proved costly, but Mitchell Starc was able to close down Andre Russell in the final over.

There was a horrendous collapse in the opening game which set the tone for the series against West Indies, and in the other matches, Australia weren't in touch. Hayden Walsh Jr was their main nemesis, although anyone taking pace off the ball stood a good chance of causing problems. With that evidence - and with what happened in Bangladesh - it would be no surprise to see oppositions stack their side with spin and pace-off options regardless of the pitches in the UAE.

During the Bangladesh series, one of the cameras caught a glimpse of Justin Langer's notebook. If there was a section reserved for positives, it would be a small one; but Marsh was outstanding with the bat, only fading in the final two innings. An often unfairly maligned player, it will be interesting to see if he can use this as a launch pad to the next phase of his career. He turns 30 in October and still has plenty of time on his side, although the Test route may now be blocked by Cameron Green - at least for now.

Yet, even Marsh's success does not really make the picture any clearer. There is no shortage of options to bat in the top four. It could yet be that Marsh needs to return to the middle order although there are suggestions that, if fit, Steven Smith could be considered in a finishing role. Such a change so close to a World Cup further highlights one of Australia's main conundrums that this tour has gone no nearer to solving.

In the bowling attack, Josh Hazlewood benefited from a run of games in the format and now looks certain to go to the World Cup. Adam Zampa held his nerve well against the power of West Indies before enjoying the pitches in Bangladesh. After picking up an injury in the West Indies, Ashton Agar was consistent in Dhaka although it remains uncertain if he has a dynamic-enough game to bat at No. 7 when needed. The return of Turner with the ball was also handy, and may yet help him in final selection.

Australia will now have to hope it all comes together at the last minute. Some of the selection challenges have been exacerbated by the Covid era, but there is still a feeling that T20 remains an uneasy fit. "It's not vital that we play games together before the World Cup," Wade said of trying to get a first-choice side together. "Don't think the difference between playing well in the World Cup or not is playing games together to know what each other is doing."

The World Cup hasn't been decided over the last six weeks. Australia certainly won't be close to favourites going into it, but they have some game-changing players to return. However, if Langer had hoped to finish this trip with a burgeoning roster of names putting pressure on those established stars, then it hasn't worked out that way.

Andrew McGlashan is a deputy editor at ESPNcricinfo