Id like to make a special note on the last Rhino he killed. He almost killed it from one application to overheated FROM THE FRONT ARMOR. BAD.
A lot of his hits to that Rhino were from the side armor, actually. And each Predator also received a melta bomb. All three vehicles were also completely stationary and undefended. Also, point-blank range. Like, melee range is further than how far away he was.
Meanwhile, I'll multimelta the shit out of vehicles with my MoS havok feeling as fast as a Fire Dragon ( ͡° ͜ʖ ͡°)
As others suggested, remove the melta bombs from the FD preset. Having a preset load out at rank 1 with a melta is already a huge benefit, having one with top notch tank killing capabilities is a bit too much, you should have to use a load out slot for it. Regarding the original post, I can't say I'm having the same difficulties catching evading eldar with my wolf priest, even less when on my skyclaw. Now, catching them BEFORE they manage to compromise/destroy their target, that's a different matter...
Actually, I've heard the Eldar presets are pretty much completely ideal for every one of their classes. They also don't have many weapon options that would make the versatility of a custom loadout a preferred option. You could probably get by as an Eldar player just fine without spending a single Advancement Point and sticking to the Preset loadouts. Personally, I use a custom loadout, but it's only so I can have a fusion pistol on my Warlock and Banshee for some anti-vehicle firepower.
Not really (they thankfully lack adv armor, warlock hasn't embolden etc), it's just that eldar classes are so monodimensional that their presets tend to cover stuff other factions have to unlock paying requisition.