OK We've all agreed on the plot holes and everything that is missing in the anime to correctly understand what was meant, but I just thought of something.

1) Actarus was sent to Moru (Pallas) as an exchange student (as it's said in the anime). Pallas would therefore be the 1st planet to be attacked by Vega. We can assume that this would be an argument in favour of Vega. Indeed, in the general bargain to obtain Grendizer if we admit that it was constructed by Fleedians, the Vegans would therefore had an edge, for example : 'if you don't give us  Grendizer then we attack you like we did to Moros, but as a proof of our goodwill, I, King Vega, offer my daughter to your son, dear King Fleed!!! '

2)The proposal is a failure : Vegalia is in love with this beautiful Prince but he isn't although he's ready to accept the sacrifice for his planet's sake. (we can also assume that this proposal was going on when Actarus was on Pallas)

3) The attack on Fleed : Vega attacks, with lazernium bombs, Actarus is contaminated with radiations, He's been already hurt on his arm during the attack on Pallas.

Those 2 attacks could have taken place in a matter of a few days or weeks, depending on the chronology we want to put in. Indeed, if we analyse the general pattern of a declaration of war, even with extremist or dictatorial regimes, there are always negotiations that give time whether to avoid or differ the conflict (ex Munich 1938) or ultimatums giving time to draft and mobilize the armies (cf 1st world war july aug 1914).

4) Fleed is attacked : the 1st step is to kill the royal family, or rather the ruling couple living 2 yound children, heirs, easily manipulatable. BUT Actarus resists, Maria is sent away. Actarus might have still been able to marry Vegalia when he had been arrested. This would make sense. Indeed, Vega wants to dominate the populations but in a way needs them : cf Planet Rubi. having the prince of Fleed as a puppet would definitely serve his purpose.  But Actarus escapes unexpectedly and steals Grendizer before the Vegan forces had even had the time to figure out how the machine worked!

5) Actarus tries to free his planet but cannot eventually he fled. He wasn't able to properly pilot G. which is conceivable since he was rather young and had never had to fight before.

I know this might seems a bit far-fetched but somehow it reconciliates all that we've been discussing on the forum.

I quite like your timeline, Jérôme, and I think it would definitely fit with the French version. According to some dialogues in the FV, Vega attempted strategies on Fleed similar to those he employs on earth: Actarus (not Daisuke) states that they used local animals which they turned into cyborgs to attack Fleed.

Of course, this too, may be a French invention. I'm sure Suzi and Gerdha will let us know about possible differences.

Dear Gerdha, I know my version is not accurate and does not fit the Japanese or italian version but somehow it fits (as Agnès wrote) the French one, and avoids the plot holes...we've been discussing a lot.

Salut Stéphane,
Indeed, it must have been a 'Blitzkrieg' or 'Lightning war' (both are used in English).
I do agree with you about Akéreb. definitely the planet must have been already conquered, because Actarus knew about its reputation (if my recollection is good!).  It could have been a penal colony, a planet located in the vicinity of Stykadès, filled with metal and energy ores, hence its conquest.