I'm not Blunderboss (Theurgist is his forum rank by the way) but I can hopefully answer your question.
Generally speaking, most builds posted on this forum will be late game builds to some extent in that they list items that aren't (easily) available in the early levels, and class abilities not available till high level. This is because the interesting item and ability combinations only appear later on; in the early-mid game you're mostly rolling with generic fine equipment and most of your class abilities aren't available yet. However that doesn't mean these builds are only horrible at lower levels. Generally speaking they'll just play like a fairly generic version of their class, and this build in no exception.
With this build in particular, you have the advantage of being a Paladin. Paladin's are very robust frontliners so you're not going to go through the painful process of being knocked unconscious on a regular basis. Your early game damage is not going to be anything to write home about, and you might be better served using a shield (Outworn Buckler bought in Gilded Vale is an obvious choice and is amazing) rather than dual wielding, though if you want to dual wield from the start of the game you certainly can. If anything, I suspect levelling this build would be less difficult than levelling others, as in the early game being flimsy is the limiting factor for a lot of classes, and the Paladin ain't flimsy.
By the way, much of the gear for this build isn't that late game. Theoretically you could pick up Bittercut at level 5 or 6, though more realistically level 8; the Gauntlets of Swift Action and Ring of Overseeing at both random loot so it's a bit down to luck, but you could get them fairly early; Sanguine Plate is from a quest in Defiance Bay that I missed in my first few playthroughs, but could be done at level 5 or 6; and Shod-in-Faith is bought from the Dwarf Smith in the Crucible Knight HQ once you've done their first quest (always do the first quest for all factions before doing the second for any of them). That's all the (!) marked items. Getting the second weapon will take longer, since Vent Pick is WM2 and you don't want to Helwax duplicate Bittercut until you've managed to make it Legendary (which requires an ingredient from WM2), but you can certainly substitute another stiletto or sabre and the build will still work. The rest of the gear can be susbtituted for something similar or simply the best item you can currently find for that slot.