Athonite does make a point regarding the quite considerable spread of experiences of the guys in this team, something that will almost certainly now be closely scrutinised.
However, the two experienced FJ guys are well know to many on this forum; I cannot imagine for one minute they would condone and undertake activity such as close formation (including take-off) and team aerobatics without being 100% certain as to the competence and abilities of those other "less experienced" team members. If there was even a hint of doubt I just cannot see them getting involved in such activity, why would they?
Regardless, it's a very sad day for all involved and sincere condolences go to family, friends and fellow team members.