Except the BoS has procurement specialists, Veronica is one of them, who are able to acquire resources and technology not available to the BoS. It'll also be much easier for them to steal and scavenge the resources after the war while the Legion and NCR are in retreat. The NCR and Legion can't take everything with them so there are going to be supply caches hidden all over the place. Fleeing NCR and Legion troops will be easy picking. Not to mention the fact that there's going to be equipment scattered all over the place from the battle. The Mojave is going to be filled with dead soldiers, as well as their guns and armor, and House's securitrons won't be able to clean up the mess until after they've made sure the area is secure. That gives BoS procurement specialists plenty of time to strip the best equipment off of dead soldiers.
What do the NCR and Legion have that would be so important to the BOS?
Funny how Benny managed to capture a securitron when House only had a handful of them and he didn't notice when one went missing from right under his nose.
when Benny took down the securitron there were lots of hostile factions (Boomers, Fiends, Great Khans, BOS, Legion, general raiders, animals) that a securitron could of been taken down by, after this though most of these factions have been subdued one way or another, or it is at least less likely that they would be able to bring one down, so if a securitron was brought down by an organised force welding energy weapons, there would be a lot less options for who it could be.
House does have a lot more securitrons than before but again, this is after the war. Some securitrons had to have been either destroyed or damaged during the fighting. That gives the BoS survivors plenty of opportunities to gather securitron parts and capture damaged securitrons.
damaged securitrons would self repair and destroyed securitrons are taken off the network
House clearly doesn't have very good defenses since the Courier can use them to sneak into his inner sanctum.
That is before House has basically unlimited electricity and a massive army of mark 2 securitrons, also that was the courier, he is the only one bad-ass enough to be able to pull that off
As for the stealthboys that would be needed, how is that a big problem? The Nightkin have regularly used them for over 100 years. You really think the BoS survivors can't get enough to use for a whole day?
it would take them more than a day to take down a securitron, use it to hack into the network, sneak from wherever they are hiding into the strip, then into the lucky 38, then to House's chamber
So? The Courier doesn't have X-Ray vision.
No, but he does have ears and I hear they are useful in finding things you can't see
And that shows he's fallible. He underestimated Inculta and Yes Man. Also, if he knew about Yes Man, why was he surprised about Benny's betrayal?
how exactly did he underestimate Vulpes? a man who posed no threat to House, only to the NCR? as for Yes Man we know House knew of him, but not about him, he was surprised at Benny's betrayal after he found out that Benny shot the courier.