Washington H. Soul Pattinson and Co Ltd (ASX: SOL) and Brickworks Ltd (ASX: BKW) are arguably two of the most interesting and impressive shares on the ASX.

At first glance, it might not seem like these two businesses are all that similar. Washington H. Soul Pattinson, or Soul Patts for short, is a diversified investing house. Whereas Brickworks is a construction materials supplier.

However, there are more similarities than meets the eye if we take a deeper dive.

The most glaring connection between these two companies is that they both own a significant chunk of the other. Yep, as it currently stands, Soul Patts has a rough 43% stake in Brickworks, while Brickworks, in turn, owns an approximate 26% chunk of Soul Patts.

This arrangement has been static for decades and was reportedly first initiated to protect both companies from corporate raiders back in the 1970s and '80s. This cross-ownership allows both companies a slice of the other's profits and dividends.

As Brickworks CEO Mark Ellinor recently stated:

Our shareholding in Soul Patts, which has been an important source of earnings and cash flow diversification for the Company for more than five decades, is expected to continue to deliver a stable and growing stream of earnings and dividends over the long term.

But there are other similarities. Both Soul Patts shares and Brickworks stock are famous for their long-term investing approach that prioritises the compounding of wealth for shareholders.

Both also have two of the best dividend streaks on the ASX.

Soul Patts is ASX dividend royalty, with a 25-year streak of increasing shareholder payouts. Brickworks can't quite boast that streak. But it can brag about not missing a dividend payment since 1962 and a still-impressive 11-year streak of growing its dividends.

Brickworks vs. Soul Patts: So which to buy?

In my view, you can't go wrong with owning either of these top-notch shares. Both have delivered significant, market-beating gains over many decades. Both companies have shown that they are prepared to forgo short-term sugar hits for the long-term wealth of shareholders. And both companies have outstanding management teams that always act with honesty and integrity.

Remember, even if you buy one of these companies, you are getting exposure to the other through that cross-ownership structure.

My personal preference is Soul Patts shares, though. Soul Patts has a far more diversified earnings base than Brickworks does, one that is not subject to the significant cyclicality of the construction industry. In addition to its Brickworks stake, Soul Patts also owns large chunks of a few other ASX stocks, including TPG Telecom Ltd (ASX: TPG) and New Hope Corporation Ltd (ASX: NHC).

The company also owns a huge and diversified portfolio of blue-chip shares, thanks to its acquisition of Milton Corporation a few years ago. Its portfolio also contains investments in private credit, venture capital and unlisted assets.

Foolish takeaway

Thanks to this incredibly broad earnings base, I think Soul Patts is the more resilient business, and that's why I own its shares as one of the largest positions in my personal portfolio.

Saying that, I would be happy to own Brickworks stock too, in addition to Soul Patts shares. Brickworks handles its volatile business cycle with aplomb and always manages to come out on top. Either way, there is no wrong choice here.