They did not, one was already making contact when using RL and the other activated it from a distance, besides, he was not confident anymore since his guard was already up when Laxus hit him with the ground attack so he was not taking any chances. You are forgetting that Acno is not like the DG as Acno is immune to basically every kind of attack while DG are still vulnerable to several kinds, so Acno is stronger and better, and for Acno while immune still acknowledged Irene’s strength which says more than what Suzaku did. August knew that Zeref with FH can stop Acno, because he could pull off the same thing as Irene since they are relatively at the same level. 2 DS are weaker than Erza, as Erza could take his lightning attacks with relative ease and react to them no less since the beginning of the series, Laxus faired no better than any other FT, heck Natsu did more harm to Hades did with LFDM, all Makarov said was Jura could give Gildarts a good match, not a matter of being on the same level, considering that Gildarts struggled and bled against a Spriggan who is roughly 1/3 his original strength, heck, Laxus was even nervous and scared when he saw the destructive power of Wall. Well all he did say was that he did train his RL, unless stated otherwise that he did more is on you. That training statement is about Natsu’s ability to memorize the fight movements of his enemies, which is not something new as we seen him do so since GMG, there are plenty of moments that he doesn’t train regularly. Because it is stated that they are all perfectly balanced to each other that two fighting would result in mutual destruction. besides, Mira’s statement is not legit until she fought him, where Jura was taken out by an explosion from Brain and Erza defeated Midnight who is likely stronger. And Mavis only said that she has not found a calculation yet to beat Jura